Merge pull request #1 from wrobstory/PR_pgshift

REF: Change 'manifest_file' to 'manifest'

ENH: Update README, fix various pieces for Py3, update setup.py

ENH: Add logic for uploading chunks and COPYing to Redshift

ENH: Add tests, dfchunker

ENH: Add package directory, test dump, setup.py, gitignore

Initial commit