DOC: improve docs, partially addressing issue #285
DOC: document returned object
TST: lengths are supposed to be equal, not almost equal
DOC: More docs on CA
DOC: references, notes about implementation for RDA
DOC: Link documentation of related methods.
DOC: PCoA scores. Closes issue #207
STY: whitespace
ENH: Add code coverage support

Add code coverage to .travis.yml via https://coveralls.io

Fixes #301

                          ________
                         | ______o|
         _______________ ||__---_||
        |  ___________  || ______ |
        | |           | |||______||
        | |#scikit-bio| ||--------|
        | |           | ||      O |
        | |           | ||      | |
        | '-----------' ||      | |
        |_____________-_||      | |
          __/_______\__  |::::::::|
         ________________'-.__
        /:::::::::':::'::\ .\\\---.
       /::======::: .:.:::\ \\_)   \
       `""""""""""""""""""`  '-----

Art via:
http://www.geocities.com/spunk1111/computer.htm
ENH: Add coverage badge
Add DataFrame support to distance-based stats.

Can now supply a grouping vector (as before) or a pandas.DataFrame and a column name to denote the grouping of objects. This makes interaction with the distance-based statistical methods more convenient in some cases (e.g., if you have a QIIME mapping file loaded as a data frame).
Add HTML table repr to results class.

For integration with IPython Notebook. Fixes #203.
add docstring for _df_to_vector

Thanks @josenavas!
ENH: Add support for test option on setup.py
ENH: Add .coveragerc file for coverage.py

Wear it: 👖
ENH: Ignore __init__.py files
MAINT: Remove -after_success section
BUG: Change skbio.test to nose.collector

Thanks NumPy!!
ENH: Add default settings to .coveragerc

Ignore a lot more things that are not useful.
ENH: Add combination of code-coverage commands

Fixes #305