Only use single version in dev

Author: jimmypuckett

composer.json

@@ -23,10 +23,10 @@
     },
     "require-dev": {
         "mockery/mockery": "^0.9.1",
-        "phpunit/phpunit": "~4.0|~5.0",
+        "phpunit/phpunit": "~5.0",
         "psy/psysh": "^0.5.1",
-        "satooshi/php-coveralls": "^0.6.1|^1",
-        "symfony/var-dumper": "~2.7|~3.0"
+        "satooshi/php-coveralls": "^1",
+        "symfony/var-dumper": "~3.0"
     },
     "autoload": {
         "psr-4": {