fix(package): update semver to version 7.1.2

Closes #247

Author: greenkeeper[bot]

package.json

@@ -17,7 +17,7 @@
     "greenkeeper-monorepo-definitions": "^1.0.0",
     "lodash": "^4.17.10",
     "require-relative": "^0.8.7",
-    "semver": "^6.0.0"
+    "semver": "^7.1.2"
   },
   "devDependencies": {
     "jest": "^23.5.0",