Revert "Merge pull request #327 from ContinuumIO/pypi-install"

This reverts commit 57eaac63d41ede5b8e7527cf32c0aa564400c89d, reversing
changes made to 84ca3b6542ef15ffe2c980fc15f04e9d91da6edc.
Revert "Add changelog additions for pypi-install branch merge."

This reverts commit f51609bc70aa23ccb1962d583eacc5516771ee7d.
Merge pull request #335 from ContinuumIO/revert_pypi_pull

Revert the pull request that merged pypi-install