Remove rc/beta suffix from composer.json files

Author: nicolas-grekas

composer.json

@@ -22,7 +22,7 @@
         "symfony/class-loader": "~3.2",
         "symfony/dependency-injection": "~3.4|~4.0",
         "symfony/config": "~3.4|~4.0",
-        "symfony/event-dispatcher": "^3.4-beta4|~4.0-beta4",
+        "symfony/event-dispatcher": "~3.4|~4.0",
         "symfony/http-foundation": "^3.3.11|~4.0",
         "symfony/http-kernel": "~3.4|~4.0",
         "symfony/polyfill-mbstring": "~1.0",