CI should validate the pod spec

.travis.yml

@@ -1,5 +1,8 @@
 language: objective-c
 osx_image: xcode6.4
+before_script:
+    - bundle install
 script:
     - xcodebuild -project SocketRocket.xcodeproj -scheme "SocketRocket" -sdk iphonesimulator -configuration Debug -PBXBuildsContinueAfterErrors=0 ACTIVE_ARCH_ONLY=0 build test
-    - xcodebuild -project SocketRocket.xcodeproj -scheme "SocketRocketOSX" -sdk macosx10.10 -configuration Debug -destination "platform=OS X" -PBXBuildsContinueAfterErrors=0 build
+    - xcodebuild -project SocketRocket.xcodeproj -scheme "SocketRocketOSX" -sdk macosx10.10 -configuration Debug -destination "platform=OS X" -PBXBuildsContinueAfterErrors=0 build
+    - pod lib lint --verbose --fail-fast

Gemfile

@@ -0,0 +1,3 @@
+source 'https://rubygems.org'
+
+gem 'cocoapods', '0.37.2'