Update semver to the latest version 🚀 (#5117)

* fix(package): update semver to version 5.6.0

* chore(package): update lockfile package-lock.json

Author: greenkeeper[bot]

package-lock.json

@@ -37,7 +37,7 @@
     "parse": "2.1.0",
     "pg-promise": "8.5.0",
     "redis": "2.8.0",
-    "semver": "5.5.1",
+    "semver": "5.6.0",
     "tv4": "1.3.0",
     "uuid": "^3.1.0",
     "winston": "2.4.1",