Increment version to v2.1.4-SNAPSHOT
Exposes payment fixture test value
[LU-66] Add merchant ID to AccessToken
[LU-73] Use PROGUARDED constant in libraries
[LU-74] Adds @NonNull to uses of Tip
[LU-81] Fix AccessToken constructor contract

Additionally:

* Suppress testAndroidTestCaseSetupProperly
* Clean up some lombok warnings
[LU-93] Add Travis continuous integration

* Sign core SDK test builds with new shared debug key
[LU-94] JSON parsing fixes and fixture clean up

* Fixes optional `Long` and `MonetaryValue` JSON parsing issues
* Fixes `JsonModelHelper.optDouble` which was returning `Double.NaN`
* Adds convenience methods to `IsoDateUtils` for parsing UTC
[LU-52] Added resource spy to injection model
[LU-109] Travis emulator image caching

* Save/boot AVDs from images in the Travis cache
* Automatically create cached image if needed and set up
  animations/lockscreen
* Use travis cache -d to clear the cache and force re-creation
* Note that PRs will use master's cache; enable branch-specific Travis
  builds and check that instead of the PR build if you need to use a
  different emulator image than master's cache.
[LU-111] Export ProGuard configuration files

* ProGuard rules are now exported automatically to consumers of SDK
  libraries
* Existing projects can continue to manually include SDK
  proguard-project.txt files but these have been deprecated in favor
  of consumerProguardFiles which does not require an explicit reference
Increment version to v2.2.0
Increment version to v2.2.1-SNAPSHOT
[LU-11] Add EnvironmentUtil.isSdk19OrGreater()

- For Attributes tests
[LU-119] Internalize Espresso; Switch to Skinny Latte

BREAKING CHANGE:

* levelUpCoreTestLib no longer exports Mockwebserver and Espresso
  dependencies
[LU-140] Fix error on action: null interstitials

* Fix a bug causing no_action interstitials to never show up in apps
* Explicitly put a JsonObject.NULL in the action of no_action 
  interstitial fixtures (match current platform behavior)
* Add explicit parsing test for no_action in InterstitialJsonFactoryTest
* Add isNull method to JsonModelHelpers
Increment version to v2.2.1
Increment version to v2.2.2-SNAPSHOT
[LU-13] Finalize draft annotations

- Matching *RequestFactory complements
-- Utils and things only used in UI are internal
-- Internals to Request/Response internal
-- Request/Response objects public
[LU-127] Use Gson model key and add factory tests