Update astropy-helpers to v1.2

[astrofrog]

This is an automated update of the astropy-helpers submodule to v1.2. This includes both the update of the astropy-helpers sub-module, and the ah_bootstrap.py file, if needed.

This is intended to be helpful, but if you would prefer to manage these updates yourself, or if you notice any issues with this automated update, please let @astrofrog know!

[astrofrog]

The Travis failure is weird (related to trying to install a Numpy RC). Will look into this.

[ejeschke]

@pllim, do you have any advice here?

[pllim]

Could it be related to astropy/ci-helpers#98? @ejeschke , try restarting the 2 failed builds and see if they succeed this time.

[pllim]

@astrofrog , any chance this can get resolved and merged?

[astrofrog]

I've rebased to restart the builds

[astrofrog]

@ejeschke @pllim - for some reason, Travis didn't update the status here, but the build passed: https://travis-ci.org/ejeschke/ginga/builds/150409763

[pllim]

@astrofrog , the commit hash mentioned in that build is different from the hash listed in this PR. Hmm.

[pllim]

But just updating the submodule is uncontroversial enough, especially given that numerous other packages already accepted the update without issues. So I think this is good to merge. 👍

[ejeschke]

Merged.

[ejeschke]

This is still having some issues on Travis, it seems. All the builds passed except Python 2.7 + SETUP_CMD='build sphinx'. It's dying with an error regarding matplotlib. Qt is not required for Ginga, so I'm not sure where the error is coming from, but it is immediately after installing astropy dev version. Stack trace below.

Collecting astropy from git+https://github.com/astropy/astropy.git#egg=astropy
  Cloning https://github.com/astropy/astropy.git to /tmp/pip-build-_C_eMm/astropy
Installing collected packages: astropy
  Running setup.py install for astropy ... done
Successfully installed astropy-1.3.dev16109
 /home/travis/miniconda/envs/test/lib/python2.7/site-packages/matplotlib/font_manager.py:273: UserWarning: Matplotlib is building the font cache using fc-list. This may take a moment.
  warnings.warn('Matplotlib is building the font cache using fc-list. This may take a moment.')
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/travis/miniconda/envs/test/lib/python2.7/site-packages/matplotlib/pyplot.py", line 114, in <module>
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
  File "/home/travis/miniconda/envs/test/lib/python2.7/site-packages/matplotlib/backends/__init__.py", line 32, in pylab_setup
    globals(),locals(),[backend_name],0)
  File "/home/travis/miniconda/envs/test/lib/python2.7/site-packages/matplotlib/backends/backend_qt4agg.py", line 18, in <module>
    from .backend_qt5agg import FigureCanvasQTAggBase as _FigureCanvasQTAggBase
  File "/home/travis/miniconda/envs/test/lib/python2.7/site-packages/matplotlib/backends/backend_qt5agg.py", line 16, in <module>
    from .backend_qt5 import QtCore
  File "/home/travis/miniconda/envs/test/lib/python2.7/site-packages/matplotlib/backends/backend_qt5.py", line 31, in <module>
    from .qt_compat import QtCore, QtGui, QtWidgets, _getSaveFileName, __version__
  File "/home/travis/miniconda/envs/test/lib/python2.7/site-packages/matplotlib/backends/qt_compat.py", line 137, in <module>
    from PyQt4 import QtCore, QtGui
ImportError: No module named PyQt4

[pllim]

@ejeschke , see astropy/astropy#5340 . The intermediate solution is to pin Travis CI to Qt4.

[pllim]

@ejeschke , see #371 for a potential fix.