updating gemlock to avoid vulnerabilities

Author: SyntaxC4

Gemfile.lock

@@ -83,9 +83,9 @@ GEM
     minitest (5.10.3)
     multi_json (1.12.1)
     nio4r (2.1.0)
-    nokogiri (1.8.0-x64-mingw32)
+    nokogiri (1.8.2)
       mini_portile2 (~> 2.2.0)
-    nokogiri (1.8.0-x86-mingw32)
+    nokogiri (1.8.2)
       mini_portile2 (~> 2.2.0)
     public_suffix (2.0.5)
     puma (3.9.1)