JARs are now properly installed into the liquipy package installation directory. Bumped up version to '0.1.3-dev'. pylint cleanup.

Fixed pylint findings.

Use package_data instead of data_files arg when calling distutils.core.setup() so that the JARs will end up inside the package;
Move externals dir inside the liquipy package;
Replace single quotes with double-quotes in executor.py per Numenta coding guidelines.

Bumped up version to '0.1.3-dev'