Add Sphinx doc building to Travis
Use an older version of Sphinx, which is known to work

This is to work around https://code.google.com/p/sympy/issues/detail?id=3623.
Echo each command from test_travis.sh
theano print Matrix and ImmutableMatrix
Merge pull request #2003 from asmeurer/travis-sphinx

Add Sphinx doc building to Travis
Merge pull request #2013 from mrocklin/theano-matrix-print

Print SymPy Matrix to Theano
Remove e.is_Add branch in limit():

    This should fix issues, like mentioned in
    https://groups.google.com/forum/?fromgroups=#!topic/sympy/61pRw1PINUA
    or issues 2641 and 3461.
test for limit(Sum(1/x, (x, 1, y)) - 1/y, y, oo), now raises NotImplementedError
Add XFAIL test for issue 3744
Tests for issues 3461 and 2641
Try to isolate gruntz bug, comment out test 8.11 (DON'T MERGE!)