Run pod lib lint on CI

Author: vbabenkoru

.travis.yml

@@ -8,4 +8,5 @@ before_install:
   - gem install xcpretty xcpretty-travis-formatter
 
 script:
-  - xcodebuild test -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone X' -workspace Iterable-iOS-SDK.xcworkspace -scheme Iterable-iOS-SDKTests CODE_SIGNING_REQUIRED=NO  | xcpretty -f `xcpretty-travis-formatter`
+  - xcodebuild test -sdk iphonesimulator -destination 'platform=iOS Simulator,name=iPhone X' -workspace Iterable-iOS-SDK.xcworkspace -scheme Iterable-iOS-SDKTests CODE_SIGNING_REQUIRED=NO  | xcpretty -f `xcpretty-travis-formatter`
+  - pod lib lint