added geom_rect. closes #171
added tests, raise exception on missing required aes as per PR comments.
updated subdir extraction in ggplot/tests/__init__.py to handle .pyc files
properly strip extension from test file basename
updated geom_rect docstring, removed redundant colour aes handling, set default face colour
updating geom_rect_plus.png to reflect default fill colour
Merge pull request #184 from funnell/geom_rect

added geom_rect. addresses #171
removed embedded formatting in README.rst hyperlinks
geom_rect: added default colour, bug fix for setting xmax, ymax outside aes(), unit test update/reorganization
changed bar's defaults to be thicker and black
Merge pull request #195 from funnell/geom_bar_visual_update

changed geom_bar's defaults to be thicker and black
Merge pull request #194 from funnell/geom_rect_test_example

geom_rect: added default colour, bug fix for setting xmax, ymax outside ...
Merge pull request #192 from funnell/readme_link_fix

removed embedded formatting in README.rst hyperlinks
Merge pull request #187 from funnell/test_path_handling

updated subdir extraction in ggplot/tests/__init__.py to handle .pyc files
removing numpy import
including brewer
cleanup
adding in scale_color_brewer
basic test for color brewer
adding dependency for brewer2mpl