add nth and friends
Merge pull request #6 from eigenhombre/master

Add travis-ci icon
Update readme installation

remove 2.5 reference

add ./setup.py install
add countby
simplify unique key doctest example
remove from itertoolz import foo from doctests
Merge pull request #2 from mrocklin/nth

add nth and friends
fix typo in countby docstring
version bump to 0.4
add forgotten imports, bump version to 0.5
PEP-8 whitespace changes
Add comp, concat, concatv, mapcat, cons and interpose, with tests.