Change to np.max
actually, should be np.maximum
Merge pull request #156 from larrybradley/fixmax

Change max to np.max
Adding tests for multiple positions (to test for #155)
adding error to aperture benchmarks
Merge pull request #157 from bsipocz/aper_adding_array_position_tests

Adding tests for multiple positions (to test for #155)
Merge pull request #158 from bsipocz/benchmark_adding_error

adding error to aperture benchmarks
adding do_rectangular_photometry function
adding do_rectangular_photometry usage to aperture_core
minor docs change
adding rectangular annulus aperture
remove check for zero lenght aperture side
Adding test
removing repeated lines
Fixing code and tests to pass tests