fix(deps): update dependency semver to v6 (#344)

Author: renovate[bot]

package.json

@@ -49,7 +49,7 @@
     "find-up": "3.0.0",
     "fs-access": "1.0.1",
     "git-semver-tags": "2.0.2",
-    "semver": "5.7.0",
+    "semver": "6.0.0",
     "stringify-package": "1.0.0",
     "yargs": "13.2.2"
   },