Add setup.py check command to the fabfile
Fix doctests for integral_steps (again)
Travis: install numpy (needed by mpl)
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.