Merge branch '2.8' into 3.4

* 2.8:
  Fix suggest.psr/*-implementation in composer.json files

Author: nicolas-grekas

composer.json

@@ -32,7 +32,7 @@
         "symfony/event-dispatcher": "",
         "symfony/lock": "",
         "symfony/process": "",
-        "psr/log": "For using the console logger"
+        "psr/log-implementation": "For using the console logger"
     },
     "conflict": {
         "symfony/dependency-injection": "<3.4",