Make travis use bazel. Attempt google#1

.travis.yml

@@ -1,14 +1,12 @@
 ---
 language: objective-c
-cache:
-  - bundler
-  - cocoapods
 sudo: false
-osx_image: xcode9.3
 
-before_install:
- - gem install cocoapods xcpretty
- - pod setup >/dev/null
+addons:
+  homebrew:
+    taps: bazelbuild/tap
+    packages: bazelbuild/tap/bazel
 
 script:
- - xcodebuild -workspace Santa.xcworkspace -scheme All -derivedDataPath build build test CODE_SIGN_IDENTITY='' | xcpretty -sc && exit ${PIPESTATUS[0]}
+ - bazel build :release
+ - bazel test :logic_tests