Make "header_keywords" argument for "_fits_summary" method mandatory

Remove unnecessary default value for keyword property setter.

Explicitly import functions (instead of star-import) in test_ccdproc test file.

Make key argument for ImageFileCollection.sort mandatory

Remove some unnecessary set calls and replace some with literals

Put import statements from function scopes at the top of the file.

Replace a dict-comprehension with a loop in ImageFileCollection

replace a multi-line ... if ... else ... construct with explicit branches

Use np.ones or np.zeros instead of np.array([bool]*length)

Raise an exception instead of silently ignoring overwrite in ccd generator

Make glob attributes of ImageFileCollection readonly

Use astropys CCDData if possible

Added new attributes to ImageFileCollection representation

Include a numpy 1.12 test in travis

Test against astropy 1.0 and 1.3

Run ImageFileCollection tests on AppVeyor

Minor cleanup in imagefilecollection tests

add slices utilities to documentation

Fix the docstring of the ccdmask function

Use build_docs instead of the deprecated build_sphinx in travis

Some parameter descriptions were missing the whitespace before the colon.
Also added default val...

Update badges to SVG

Update astropy-helpers to v2.0.1

Update astropy-helpers to v2.0

Added sum combiner (#500)

Fixed triple quotes to double quotes

Adding LICENSE to manifest [ci skip]

Update reduction_toolbox.rst

Missing backticks made sphinx not render a link.

[skip ci]

numpy.ndarray as an input for combine [#493]

Remove several properties already present in NDDataArray

Use the generic ci-helpers script

fix unneeded compatibility import

There were three blank lines after ``test_combine_numpyndarray``, so deleted one.
An item in CHA...

Using system pytest rather than astropy bundled

Add multi-extension support

Fix sip wcs handling

Closes #457

Fix failures in astropy-dev tests

Closes #498

Closes #496

Add __repr__ method to ImageFileCollection