Revert "BF: force gcc for compile"

This reverts commit 5a0e2e1afae2eb6710eaf9e9fbe3ef798e11c23a.

gcc / clang isn't the problem, in fact, it is the numpy version.
NF: update python 2.7 dependency to 1.7.1

See: https://github.com/pydata/pandas/issues/7847