Bump version Gradle to 4.10.3 and Robolectric to 4.1

[TonyTangAndroid]

Bump version Gradle to 4.10.3 and Robolectric to 4.1.

All unit tests are passed. The logger issue is actually rooted from ASOP, which pollutes our test cases.
I updated the assertion to make it pass.

This pull request construes the minimum changes to support the latest gradle, Android and Robolectric and is ready to be merged.

I will make another pull request to optimize the build script.

[TonyTangAndroid]

I have more following up pull request to add up. But I would like to hold on until we resolve this pull request.

[davidgyoung]

Sorry for the delay in reviewing, @TonyTangAndroid, I am just getting caught up after the holidays.

I do see one unit test failing in my dev environment:

MonitoringStatusTest.java
allowsAccessToRegionsAfterRestore
java.lang.AssertionError: beaconManager should return restored regions expected:<50> but was:<0>

The only code change I see you made is to use

Context context = RuntimeEnvironment.application; instead of Context context = ShadowApplication.getInstance().getApplicationContext();

This test verifies that the library can serialize 50 regions to a file (in the app directory) and then deserialize it. I'm not sure why that is failing, but perhaps this different context in Robolectric no longer has access to the file system.

I saw in a comment you said you thought this was a "flaky test". Does this mean you saw it failing intermittently? Do you see this passing locally with this branch?

[TonyTangAndroid]

If you run the failed test independently, it will pass. If you run all the test all together, it will fail. If you run to the failed test continuously for 10 times, it will only pass for the first time. I tried to find the cause, but to no prevail.

[davidgyoung]

I was able to fix the intermittently failing unit tests by more clearly setting the initial conditions in the before method, and consistently accessing the same object in all tests.

[TonyTangAndroid]

Awesome! That is very good to know. I would like to make more pull request related to sample code. We could discuss more in the corresponding thread.

[davidgyoung]

sounds good, @TonyTangAndroid