Initial commit
Implementation of CA, RDA and CCA.

Broadly, the main structure is a super class that know how to plot biplots
(ordination results), and then subclasses that implement an
scores method that computes a standard set of results.
TST: Add testing files

There're still some more tests to be added, in particular for RDA
and CCA.
Make package installable (add setup.py)
DOC: Update readme
BUG: Update __main__ in base.py so that examples work.

It's a bit ugly (because pretty much the same function is in
test_ordination). Ideally we'd have a function `get_data_path` in
utils that would give you the path to the caller (using inspect,
I think).
MAINT: Ignore temporary files
DOC: Add some usage instructions
STY: clean up whitespace
DOC: Raw string needed
MAINT: Make version compatible with PEP386
TST: Make tests runnable with either py.test or nose.
MAINT: change README file extension.
DOC: Improve testing instructions.
ENH: Add travis.ci integration.

It uses miniconda to avoid having to spend time bulding numpy et al.
ENH: Improve travis-ci integration.
BUG: conda shouldn't ask for confirmation.
BUG: Fix wrong miniconda link.
MAINT: pytest not available in miniconda's py3.
DOC: Add travis-ci status.