add ruby and pod versions to travis yml

Author: morganchen12

.travis.yml

@@ -3,6 +3,10 @@ language: objective-c
 xcode_workspace: FirebaseUI.xcworkspace
 xcode_scheme: FirebaseUI
 
+rvm: 2.3.1
+before_install:
+  - gem install cocoapods -v '1.0.1'
+
 script: xcodebuild -workspace FirebaseUI.xcworkspace
   -scheme FirebaseUI
   -sdk iphonesimulator