Merge pull request #10 from square/whatsemo/update-dependencies

Update to IAP 1.2.0 and use v28 support libraries

Update Gradle and stop using "NotNull"

Update to 1.1.0

Bump Gradle, AGP, and Retrofit

Remove redundant repositories from build.gradle's

Updated README to include link to quickstart guide. (#3)

Merge pull request #2 from square/ella/update-android-1.0.3

Update the In-App Payments SDK version to 1.0.3

Merge pull request #1 from square/ella/update-android

Update the In-App Payments SDK Version.

Initial Import