Make CSS files/path configurable

Added config options to readme

corrected order of assert params

added another test css
Format code

Format code
prevent catching callback test errors
changed test size to only include header nav
fixed fixtures
Fixed tests

 - strip whitespace before comparing styles
 - changed tested size to 320 x 70 to only include the header
some code formatting
Merge pull request #22 from bezoerb/ConfigureCssFolder

Configure CSS folder/file