Merge pull request #18 from zblz/template-merge

Merge astropy affiliated package template
add travis badge to README
Merge pull request #21 from zblz/travis

add travis badge to README
fix corner import
Merge pull request #22 from zblz/corner-plot

fix corner import
add coverage badge
core.py and plot.py docstrings
Merge pull request #24 from zblz/docstrings2

core.py and plot.py docstrings
core.py coding
update astropy_helpers
fix docstring reference in See also section
use astropy hack to import astropy_helpers when building docs from docs directory
include examples in tutorial