Bumps composer versions as per Issue 1052 (#122)

* update migrate plugins

* update prepopulate module

composer.json

@@ -21,11 +21,11 @@
     "stomp-php/stomp-php": "4.*",
     "drupal/jwt": "1.0.0-alpha6",
     "drupal/filehash": "^1.1",
-    "drupal/prepopulate" : "^2.0@alpha",
+    "drupal/prepopulate" : "^2.2",
     "drupal/eva" : "^1.3",
     "drupal/features" : "^3.7",
-    "drupal/migrate_plus" : "4.0-beta3",
-    "drupal/migrate_tools" : "4.0-beta3",
+    "drupal/migrate_plus" : "^4.1",
+    "drupal/migrate_tools" : "^4.1",
     "drupal/migrate_source_csv" : "^2.1",
     "drupal/token" : "^1.3",
     "drupal/flysystem" : "^1.0",