Trackpy

This is the first trackpy release to support Python 3.6. It is identical to v0.3.2 except for a minor fix for Python 3.6 compatibility that does not change any scientific functionality.

This release contains a number of bugfixes and enhancements: pair correlation functions, faster mean squared displacement calculations, and an increase of feature finding precision. See http://soft-matter.github.io/trackpy/v0.3.1/whatsnew.html for a full overview of the changes.

This release is strongly recommended for all users, as it brings major improvements in speed and 3D feature-finding, and many other functionality and accuracy improvements.

Please be sure to read the "What's New" page in the [documentation](http://soft-matter.github.io/trackpy/0.3.0/) before upgrading, especially the item under "Enhancements" about calculating masses. You may have to make minor edits to your scripts and notebooks to use them with v0.3.

If you are an Anaconda user, upgrading is as simple as "conda update -c soft-matter trackpy". Other methods are shown on the Installation page in the [documentation](http://soft-matter.github.io/trackpy/0.3.0/).

This is a simple maintenance release, introducing no functionality changes. The packaging and installation are simplified.

Henceforth, to install trackpy on any platform, we recommend `conda install -c soft-matter trackpy`, but `pip install trackpy` is also supported.

This release contains some important improvements, cleanup, and bug fixes:
- Compatibility with Python 3, official support for Python 2.7 and 3.4
- More efficient storage of frame-wise data in HDF format (~40X smaller files)
- Better-looking and more flexible `annotate` function for inspecting feature locations
- Cleaner installation and version-number handling (thanks, leouieda )
- Various minor bug fixes