Merge pull request #1 from dmnielsen/master

Added median function to stats.py
I've added tests for your awesome median function.
I added a median test to make sure the median of 1 number is that number.
Merge pull request #2 from astrophysaxist/median_tests

Median tests
Merge pull request #2 from SimonGoring/master

A pull request to add tests for the median function.