Fix upsample for factors > 2
Added image sampling tests
Fixed typos in testing docs
Combined downsample and upsample in sampling.pyx
Fixed downsample imports
Merge pull request #76 from larrybradley/sampling-tests

Added image sampling tests
Mark tests that require scikit-image
Merge pull request #78 from cdeil/skimage_skip_tests

Mark tests that require scikit-image
Fixed a test in test_core
Test adding .coveragerc
Fixed .coveragerc syntax to remove all tests from coverage
Add *version.py to .coveragerc
Merge pull request #82 from larrybradley/coveragerc

Add .coveragerc
Add photutils.datasets sub-package
Add fermi_counts.fits.gz example image file
Add datasets sub-package to docs
Various improvements to datasets code and docs