Update Ruby dependencies

bundle install failed on my machine because I use ruby 2.4.1 and the
json gem version 1.8.3 was not compatible.

This problem has now been fixed:
ruby/json#303

Gemfile.lock

@@ -1,14 +1,13 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    CFPropertyList (2.3.4)
-    activesupport (4.2.7.1)
+    CFPropertyList (2.3.5)
+    activesupport (4.2.8)
       i18n (~> 0.7)
-      json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    addressable (2.5.0)
+    addressable (2.5.1)
       public_suffix (~> 2.0, >= 2.0.2)
     claide (1.0.1)
     claide-plugins (0.9.2)
@@ -39,23 +38,24 @@ GEM
       fuzzy_match (~> 2.0.4)
       nap (~> 1.0)
     cocoapods-deintegrate (1.0.1)
-    cocoapods-downloader (1.1.2)
+    cocoapods-downloader (1.1.3)
     cocoapods-plugins (1.0.0)
       nap
     cocoapods-search (1.0.0)
     cocoapods-stats (1.0.0)
-    cocoapods-trunk (1.1.1)
+    cocoapods-trunk (1.2.0)
       nap (>= 0.8, < 2.0)
       netrc (= 0.7.8)
     cocoapods-try (1.1.0)
     cocoapods-update-if-you-dare (0.1.1)
     colored (1.2)
-    cork (0.2.0)
-      colored (~> 1.2)
-    danger (4.0.3)
+    colored2 (3.1.2)
+    cork (0.3.0)
+      colored2 (~> 3.1)
+    danger (5.2.1)
       claide (~> 1.0)
       claide-plugins (>= 0.9.2)
-      colored (~> 1.2)
+      colored2 (~> 3.1)
       cork (~> 0.1)
       faraday (~> 0.9)
       faraday-http-cache (~> 1.0)
@@ -69,15 +69,15 @@ GEM
     danger-plugin-api (1.0.0)
       danger (> 2.0)
     escape (0.0.4)
-    faraday (0.10.0)
+    faraday (0.12.1)
       multipart-post (>= 1.2, < 3)
     faraday-http-cache (1.3.1)
       faraday (~> 0.8)
     fourflusher (2.0.1)
     fuzzy_match (2.0.4)
-    gh_inspector (1.0.2)
+    gh_inspector (1.0.3)
     git (1.3.0)
-    i18n (0.7.0)
+    i18n (0.8.1)
     jazzy (0.8.1)
       cocoapods (~> 1.0)
       mustache (~> 0.99)
@@ -87,20 +87,20 @@ GEM
       sass (~> 3.4)
       sqlite3 (~> 1.3)
       xcinvoke (~> 0.3.0)
-    json (1.8.3)
-    kramdown (1.13.1)
+    json (1.8.6)
+    kramdown (1.13.2)
     liferaft (0.0.6)
-    minitest (5.10.1)
-    molinillo (0.5.4)
+    minitest (5.10.2)
+    molinillo (0.5.7)
     multipart-post (2.0.0)
     mustache (0.99.8)
     nanaimo (0.2.3)
     nap (1.1.0)
     netrc (0.7.8)
-    octokit (4.6.2)
+    octokit (4.7.0)
       sawyer (~> 0.8.0, >= 0.5.3)
     open4 (1.3.4)
-    public_suffix (2.0.4)
+    public_suffix (2.0.5)
     rake (12.0.0)
     redcarpet (3.4.0)
     rouge (1.11.1)
@@ -112,18 +112,17 @@ GEM
     sqlite3 (1.3.13)
     terminal-table (1.7.3)
       unicode-display_width (~> 1.1.1)
-    thread_safe (0.3.5)
-    tzinfo (1.2.2)
+    thread_safe (0.3.6)
+    tzinfo (1.2.3)
       thread_safe (~> 0.1)
-    unicode-display_width (1.1.2)
+    unicode-display_width (1.1.3)
     xcinvoke (0.3.0)
       liferaft (~> 0.0.6)
-    xcodeproj (1.4.1)
+    xcodeproj (1.4.4)
       CFPropertyList (~> 2.3.3)
-      activesupport (>= 3)
       claide (>= 1.0.1, < 2.0)
-      colored (~> 1.2)
-      nanaimo (~> 0.2.0)
+      colored2 (~> 3.1)
+      nanaimo (~> 0.2.3)
 
 PLATFORMS
   ruby
@@ -137,4 +136,4 @@ DEPENDENCIES
   rake
 
 BUNDLED WITH
-   1.13.6
+   1.14.6