change default from np.median to np.ma.median
In ascii.read(), recognize list containing a newline

The `BaseInputter` class tries to detect whether the input is a file
object, filename, or iterable. However it can be fooled into thinking
that the input is a filename if it is a list of strings, one of which is
a newline.
Added new contributors
Added more contributors
Fix a segfault in `astropy.wcs._wcs`.

At a certain point in our test suite, the interpreter stops
being able to allocate even fairly small objects.  I haven't
gotten to the bottom of why that is, but this fix at least
prevents that case from becoming an out-and-out segfault.
Fix "'astropy' not loaded, cannot perform relative import" error in test
suite.

This fixes an occasional issue we've seen on Travis where one sees:
"'astropy' not loaded, cannot perform relative import".  I was able to
reproduce it consistently, by installing and running the tests with
`python -c "import astropy; astropy.test()"`.

The issue here is that when the `test/test_imports.py:test_imports` test
runs, it ends up importing astropy for a second time (i.e. reloading).
I'm not sure why, but `astropy` is not in `sys.modules` at that
point (though many of its submodules are) so it effectively does a
reload.  This reload causes it to try to write the configuration file
again.  The problem is that we have a `py.test` fixture that creates a
new temporary directory to store the config file and then deletes it
when done on each and every test.  So when astropy is reloaded, it tries
to create a config file in the old temporary directory (used by an
earlier test in the `configuration` subpackage), but now that temporary
directory no longer exists (since the location of all loaded
configuration files is cached, its location really can not change during
the life of the interpreter).

There are two independent ways to fix this, and I would advocate doing
both:

- 1. Don't update the config file if the config file directory doesn't
     exist.  (There is already code to create the config directory in
     the "normal" case, but it falls down here because the temporary
     config directory gets deleted underneath us).  That is a corner
     case that I don't think we have to handle.

- 2. Remove the py.test fixture that creates a temporary configuration
     directory with each test.  There is already code to do this for the
     entire test run, and I don't see the need to do this more than
     once.  It saves a lot of busy work and system calls if nothing
     else.
Merge pull request #2665 from mdboom/wcs/fix-segfault

Fix a segfault in `astropy.wcs._wcs`.
Merge pull request #2666 from mdboom/test/fix-importing-problem

Fix "'astropy' not loaded, cannot perform relative import" error in test
Fixed astropy_helpers submodule at astropy-helpers v0.4rc2
Do the Sphinx version check ourselves.

The one built in to Sphinx only handles major.minor.
Merge pull request #2667 from mdboom/doc/sphinx-version-check-ourselves

Do the Sphinx version check ourselves.
Add unit test
Add changelog entry
PR to test Astropy build against what will be tagged astropy-helpers v0.4rc3
Merge pull request #2669 from embray/update-ah

Update astropy-helpers to v0.4rc3
Merge pull request #2648 from lpsinger/read_ascii_list_with_newline

In ascii.read(), recognize list containing a newline
Merge pull request #2562 from astrofrog/update-contributors

Update contributor list
Explicitly use os.linesep in the expected value since that's what's used by the writer code
Just use a common random seed.  Some of these tests (particularly the ones using 0xDEADBEEF as a seed) were being hit by a common bug in some versions of Numpy where Python long objects (which a value like 0xDEADBEEF is converted to on 32-bit systems) are not handled properly by Numpy since it can't guarantee they will fit into a machine integer type
This test wasn't actually making using use of the parametrization; though one of the fitters seems to be failing badly on Win32...