- Publish latest changes and upgrade libs

Merge pull request #1 from reines/mkdir

Ensure we create the cache dir before attempting to use it - not all environments will have ${HOME}/.aws/ directories already

Add publish plugin and idea

Added plugin bundle for gradle plugin upload

Fix the functional test so it properly tests the results.

* Migrate gradle wrapper back to 5.6.4 just to make the plugin most broad reach

First pass at adding the ECR Token Plugin.