diff --git a/composer.json b/composer.json
index 0f72887..ddcd334 100644
--- a/composer.json
+++ b/composer.json
@@ -17,6 +17,11 @@
 		"issues": "https://github.com/pressbooks/pressbooks-aldine/issues",
 		"forum": "https://discourse.pressbooks.org/"
 	},
+	"config": {
+		"platform": {
+			"php": "7.0.27"
+		}
+	},
 	"require": {
 		"php": ">=7",
 		"composer/installers": "~1.0",
diff --git a/composer.lock b/composer.lock
index 868b92f..8573413 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "328c4def8b886443aef3280c80ff5fa8",
+    "content-hash": "055e0d205a16f08b328ff9d4e80e0bcf",
     "packages": [
         {
             "name": "composer/installers",
@@ -365,6 +365,53 @@
             ],
             "time": "2018-07-13T14:56:39+00:00"
         },
+        {
+            "name": "psr/log",
+            "version": "1.0.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/php-fig/log.git",
+                "reference": "4ebe3a8bf773a19edfe0a84b6585ba3d401b724d"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/php-fig/log/zipball/4ebe3a8bf773a19edfe0a84b6585ba3d401b724d",
+                "reference": "4ebe3a8bf773a19edfe0a84b6585ba3d401b724d",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.0"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.0.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Psr\\Log\\": "Psr/Log/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "PHP-FIG",
+                    "homepage": "http://www.php-fig.org/"
+                }
+            ],
+            "description": "Common interface for logging libraries",
+            "homepage": "https://github.com/php-fig/log",
+            "keywords": [
+                "log",
+                "psr",
+                "psr-3"
+            ],
+            "time": "2016-10-10T12:19:37+00:00"
+        },
         {
             "name": "squizlabs/php_codesniffer",
             "version": "3.3.0",
@@ -418,20 +465,21 @@
         },
         {
             "name": "symfony/console",
-            "version": "v4.1.2",
+            "version": "v3.4.13",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/console.git",
-                "reference": "5c31f6a97c1c240707f6d786e7e59bfacdbc0219"
+                "reference": "e54f84c50e3b12972e7750edfc5ca84b2284c44e"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/console/zipball/5c31f6a97c1c240707f6d786e7e59bfacdbc0219",
-                "reference": "5c31f6a97c1c240707f6d786e7e59bfacdbc0219",
+                "url": "https://api.github.com/repos/symfony/console/zipball/e54f84c50e3b12972e7750edfc5ca84b2284c44e",
+                "reference": "e54f84c50e3b12972e7750edfc5ca84b2284c44e",
                 "shasum": ""
             },
             "require": {
-                "php": "^7.1.3",
+                "php": "^5.5.9|>=7.0.8",
+                "symfony/debug": "~2.8|~3.0|~4.0",
                 "symfony/polyfill-mbstring": "~1.0"
             },
             "conflict": {
@@ -440,11 +488,11 @@
             },
             "require-dev": {
                 "psr/log": "~1.0",
-                "symfony/config": "~3.4|~4.0",
+                "symfony/config": "~3.3|~4.0",
                 "symfony/dependency-injection": "~3.4|~4.0",
-                "symfony/event-dispatcher": "~3.4|~4.0",
+                "symfony/event-dispatcher": "~2.8|~3.0|~4.0",
                 "symfony/lock": "~3.4|~4.0",
-                "symfony/process": "~3.4|~4.0"
+                "symfony/process": "~3.3|~4.0"
             },
             "suggest": {
                 "psr/log-implementation": "For using the console logger",
@@ -455,7 +503,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "4.1-dev"
+                    "dev-master": "3.4-dev"
                 }
             },
             "autoload": {
@@ -482,7 +530,63 @@
             ],
             "description": "Symfony Console Component",
             "homepage": "https://symfony.com",
-            "time": "2018-07-16T14:05:40+00:00"
+            "time": "2018-07-10T14:02:11+00:00"
+        },
+        {
+            "name": "symfony/debug",
+            "version": "v3.4.13",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/debug.git",
+                "reference": "0e3ca9cbde90fffec8038f4d4e16fd4046bbd018"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/debug/zipball/0e3ca9cbde90fffec8038f4d4e16fd4046bbd018",
+                "reference": "0e3ca9cbde90fffec8038f4d4e16fd4046bbd018",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^5.5.9|>=7.0.8",
+                "psr/log": "~1.0"
+            },
+            "conflict": {
+                "symfony/http-kernel": ">=2.3,<2.3.24|~2.4.0|>=2.5,<2.5.9|>=2.6,<2.6.2"
+            },
+            "require-dev": {
+                "symfony/http-kernel": "~2.8|~3.0|~4.0"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "3.4-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Component\\Debug\\": ""
+                },
+                "exclude-from-classmap": [
+                    "/Tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Symfony Debug Component",
+            "homepage": "https://symfony.com",
+            "time": "2018-06-26T08:45:54+00:00"
         },
         {
             "name": "symfony/polyfill-mbstring",
@@ -693,5 +797,8 @@
     "platform": {
         "php": ">=7"
     },
-    "platform-dev": []
+    "platform-dev": [],
+    "platform-overrides": {
+        "php": "7.0.27"
+    }
 }