Disable strictmode and leak canary for CI testing

[tobrun]

We are using both LeakCanary and Strict mode to make our code more robust but these tools interfere with our automated tests on CI. We need to look into disabling these during tests.

[tobrun]

From square/leakcanary#143:
The following configuration should disable LeakCanary during instrumentation tests:

    androidTestCompile 'com.squareup.leakcanary:leakcanary-android-no-op:1.4-beta'
    debugCompile 'com.squareup.leakcanary:leakcanary-android:1.4-beta1'
    releaseCompile 'com.squareup.leakcanary:leakcanary-android-no-op:1.4-beta1'

[tobrun]

Regarding Strictmode, I'm unable to find a clean solution to detect if code is executed as part of a instrumentation test. Going to proceed with LeakCanary fix from above.