Squashed affiliated docs reformatting into one commit
installed "configurable docs"

attempt to fix RTD issues: remove -e in front of astropy repo path

Reverted use of configurable logo for testing RTD

installed "configurable docs"

(squash all RTD bugfix commits)
attempt to fix RTD issues: remove -e in front of astropy repo path

Reverted use of configurable logo for testing RTD

attempt to use @eteq's build-ext fix branch

try/except around import coords, EVEN THOUGH it's mocked out

revert to astropy/master which now has #725 incorporated

now back to @kbarbary's configurable-logo

tried adding kbarbary's branch to pip-requirements

changed pip requirements to astropy master

revert pip-requirements to just be astropy, and rtd-pip-requirements to
latest astropy