Add release artifact to travis build

[codeallthethingz]

As this project is managed by maven, the lib folder seems to bloat the project unnecessarily.
I may be wrong but the reason the lib folder seems to exist is to have a runnable version of the product at git checkout. I feel that having a runnable version of the product should be accomplished by releasing a tagged version of the product that can be downloaded from the github release page. This tagged version can be automatically created as part of the travis build process and then downloaded and run with a simple java -jar htm.java-X.X.X.jar or, alternatively/additionally, download a tagged zipped version with included dependencies. htm.java-X.X.X-with-dependencies.zip

lf this makes sense I'd like to have a go at:

1. Updating the travis build to include releasing artifacts: Travis + Github Releases
2. Remove the libs folder
3. Provide a script to the numenta git admin to obliterate the lib folder from git history so checkouts are nice and fast.