fix another packaging issue
bump version to 1.3.1
DOC fix sphinx formatting
test utils: Added print_output function to Splash & Mock server class.
TST print output on shutdown for non-fixture servers; remove time.sleep
utils: added helper functions.
- ViewPort parser function which takes viewport in WxH format and return W and H.
- Display profile to viewport converter.
render_options: added geometry option getter helper function.
BrowserTab sets created web view geometry based on request parameters.
test: created a baseclass for js related tests.
Added geometry tests.