Adding Rick to authors. Welcome!
Merge pull request #2254 from raoulb/fix_atan2

Fix and extend the atan2 function.
Merge pull request #2243 from jrioux/design

Replace Class(*args) by self.func(*args).
Rewrite atan2 as arg function
Improve rewrite of atan2 in terms of arg
Test rewrite to arg
Eval conjugates of atan2 expressions
Adding some files
Adding liealgebras to setup.py
Add a docstring
Revert "Checkout 0.7.3 before testing in Travis"

This reverts commit 3d56d4b8c1d8346bc92bc23487cbb82214c6c476.
Merge branch 'master' into matrix_hash

Conflicts:
	sympy/matrices/tests/test_matrices.py
Merge branch 'matrix_hash' of github.com:asmeurer/sympy into matrix_hash
Merge pull request #2274 from lidavidm/issue_3943

Issue 3943: document integral_steps, which Gamma uses
Typo agregator -> aggregator.
Typo python -> Python.
Typo: look this -> look at this.
Rework infinitesimals docstring.
Fix dsolve reference under Hint Functions.
Fix logcombine reference.