downgrade the required symfony packages versions

Author: Mulkave

composer.json

@@ -17,9 +17,9 @@
     "bin": ["lucid"],
     "minimum-stability": "stable",
     "require": {
-        "symfony/console": "^2.7|^3.1",
-        "symfony/process": "^2.7|^3.1",
-        "symfony/finder": "^2.7|^3.1",
+        "symfony/console": "^2.7|^3.0",
+        "symfony/process": "^2.7|^3.0",
+        "symfony/finder": "^2.7|^3.0",
         "stevebauman/log-reader": "^1.1",
         "phploc/phploc": "^3.0"
     }