Update version_gem to version 1.1.8

Author: depfu[bot]

Gemfile.lock

@@ -135,7 +135,7 @@ GEM
       unicode-emoji (~> 4.0, >= 4.0.4)
     unicode-emoji (4.0.4)
     uri (0.13.2)
-    version_gem (1.1.7)
+    version_gem (1.1.8)
     webrick (1.9.1)
     yard (0.9.37)
     yard-junk (0.0.10)