Changed Scripts to upload in jcenter automatically

[PrashamTrivedi]

Hi as per I have commented in your blog post, I have changed script such a way that it can read properties everywhere, without writing in local.properties, and even does not require ext block.

Here are some changes I have done

• Directly accessing all the properties rather than depending on ext block
• also added afterEvaluate callback where all the properties from build.gradle can be accessed without fail
• Bintray properties had to be renamed because they were not working with dots(.)
• Added readme for better instructions.

I have uploaded couple of projects using it, and added a sample link in readme which refers to my forked repository right now. Once the PR is merged I am willing to change scripts URL.

Thanks