Add support for AppCompat ver. 1.2.0

[pr0t3us]

This PR fixes JcMinarro#23 and JcMinarro#35.

Changes

• Increased AppCompat version to 1.2.0 and adjusted the context wrapping based on changes described in this answer.

Instead of the old approach with attachBaseContext override 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())

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

Screenshots

Before	After

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.

[ffelini]

LGTM 👍