Update package contents to provide better support for contributors

[cmlccie]

Need to do the following here:

• Update Versioneer version numbering scheme to automate maintenance release numbering
• Add package requirements.txt (packages needed on a contributors workstation)
• Add authors.rst
• Update .gitignore (remove unused entries)
• Provide a complete test suite (separate effort)
• Provide developer docs
  • Contribution workflow document
  • Sphinx internal API docs