Remove kotlin plugin from library

[joielechong]

For the library module, I think you can safely remove the apply plugin: 'kotlin-android' and implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version" from dependencies. I try running the sample app with the two above removed and the app is running smoothly.

I can send you a PR to let me remove them.

[hedzr]

You're right, @joielechong , that's my bad.
Waiting for the PR on master, we would release it with our works.

[joielechong]

@hedzr: I have create a PR.. please take a look. ;)

[joielechong]

Thanks for the merge!