added tests directory with snapshot test and test file
coverage for Portal will be at 100% after this PR is merged
note: noticed that it doesn't appear that the style prop is used anywhere, but did not remove it from propTypes. If you think I should do that, let me know.
ProgressBar:
removed propType definition and default for multiColor, since code does nothing with it and it makes me sad everytime I see it and know I can't have a rainbow progress bar
added tests directory, snapshot test and test file
coverage for ProgressBar will be at 100% after this PR is merged
Portal:
ProgressBar: