Add support for AppCompat ver. 1.2.0

[pr0t3us]

This PR fixes #23 and #35.
Increased AppCompat version to 1.2.0 and adjusted the context wrapping based on changes described in this answer.

Changes

Instead of the old approach with override attachBaseContext from Activity - declare PhilologyAppCompatDelegateHolder in BaseActivity and supply the right delegate for androidx.appcompat.app.AppCompatActivity#getDelegate method:

    private val delegateHolder = PhilologyAppCompatDelegateHolder()
    override fun getDelegate() = delegateHolder.getDelegate(super.getDelegate()) {
        ViewPumpContextWrapper.wrap(Philology.wrap(it))
    }

The wrapped context will be reused inside activity on each getDelegate call.

Note:
⚠️ I've pinpointed CircleCi image to the latest successful docker image build before Update Java from v8 to v11. (#500) since it's incompatible with current Robolectric version

How to test

1. Run the sample app (updated to AppCompat ver. 1.2.0)
2. Philology should replace the text in the sample app based on the device locale.