test_KGML_graphics.py: added comment to indicate reuse of class in online tests.
test_KGML_graphics.py: removed test_render_KGML_import_map test, for placement in online test module
test_KGML_graphics.py: shortened docstring
test_KGML_graphics.py: Modified copyright string, and test docstring
test_KGML_graphics.py: Fixed docstring typo.
test_KGML_graphics_online.py: Split test with online requirements from main test.