Tokenizer now in elit project

[imgarylai]

Proposed Changes

• Use pybind11 as our cxx-python integration method.
• Move all resources files under elit/resources/ path. However, I don't include all resources files in the build version in this stage because I think some resource files need to be removed. To add resource files you need, place files under the directory and go to setup.py; add your resource files to package_data inside metadata dict.

  package_data={'': ['resources/tokenizer/*.txt']},

  Ref: https://docs.python.org/2/distutils/setupscript.html#installing-package-data