Added tag 3.7 for changeset 49bd27eebf21
Use compat's StringIO. Should fix bitbucket #213

https://bitbucket.org/pypa/setuptools/issue/213/regression-setuptools-37-installation

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extra : source : 182f68beacf5e436609fb7d1064a18279cbbd24a
Bumped to 3.7.1 in preparation for next release.
Update changelog