Aotools

- Fixed a bug in the centreOfGravity function
- Changed centreOfGravity to take threshold as an optional argument (defaults to no threshold)
- Added code of conduct
- Added open source licence
- Updated documentation

- Updates to Zernike calculations (thanks GillesOrban )

- Bug fixes for encircled energy functions (thanks GillesOrban !)

- Slope Covariance Generation Fixes (thanks andrewpaulreeves )

- Add phase structure function calculation (thanks GillesOrban !)
- Add encircled energy calculation (thanks GillesOrban !)
- Increased test code
- Improved documentation
- Bug fixes

- Automate pypi release using travis
- Fix PyPi description