Issue-43: IntelliJ plugin supports both new and legacy package names

[DanielJette]

What does this change accomplish?

Add support for both new and legacy package names to the IntelliJ plugin.
Resolves #43

How have you achieved it?

Users will likely take some time to migrate from the com.shopify namespace to the new dev.testify namespace. During this transition, they may be using newer versions of Android Studio (Dolphin, Electric Eel) which are not supported by the legacy plugin. To facilitate this transition, the plugin can support both new and legacy package names.

Tophat instructions

1. In any supported version of Android Studio, install the pre-built plugin from IntelliJ-1.2.0-alpha02.jar.zip

New package

1. Open the current Sample source code in the preview build of Android Studio.
2. Verify that the 📷 icon is present in the screenshot test files and that the various commands work as expected.

Legacy Package

1. Checkout the legacy codebase from https://github.com/Shopify/android-testify
2. Open the legacy project Sample
3. Verify that the 📷 icon is present in the screenshot test files and that the various commands work as expected.

[DanielJette]

IntelliJ-1.2.0-alpha02.jar.zip

[jaredh]

Works as described 👍