Update Gemfile.lock - fix security alerts

Author: CodyReichert

Gemfile

@@ -1,5 +1,5 @@
 source 'https://rubygems.org'
-ruby '2.4.0'
+ruby '2.5.3'
 
 gem 'sinatra', '~>1.4.4'
 gem 'json'

Gemfile.lock

@@ -1,15 +1,15 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    json (2.0.2)
-    rack (1.6.5)
-    rack-protection (1.5.3)
+    json (2.1.0)
+    rack (1.6.11)
+    rack-protection (1.5.5)
       rack
     sinatra (1.4.8)
       rack (~> 1.5)
       rack-protection (~> 1.4)
       tilt (>= 1.3, < 3)
-    tilt (2.0.7)
+    tilt (2.0.8)
 
 PLATFORMS
   ruby
@@ -19,7 +19,7 @@ DEPENDENCIES
   sinatra (~> 1.4.4)
 
 RUBY VERSION
-   ruby 2.4.0p0
+   ruby 2.5.3p105
 
 BUNDLED WITH
-   1.14.6
+   1.17.1