I tried a clean version of both the app master and the EasyOpenCV sdk's and I get an error where the script release-aar.gradle isn't a thing. It's apparently located in the ftc_app-master folder.
You should not need to locally clone EasyOpenCV unless you want to work on developing EasyOpenCV itself. Otherwise, simply follow the installation instructions in the readme.
I tried a clean version of both the app master and the EasyOpenCV sdk's and I get an error where the script release-aar.gradle isn't a thing. It's apparently located in the ftc_app-master folder.