Tests for extending workflow could previously fail when they called "python /some_directory/tuttle-extend-workflow" if running under a python other than the one in the path (especially if default python is 3). Changed to call the python we're running under.
Also quotes paths so it works with spaces in them.
Tests for extending workflow could previously fail when they called "python /some_directory/tuttle-extend-workflow" if running under a python other than the one in the path (especially if default python is 3). Changed to call the python we're running under.
Also quotes paths so it works with spaces in them.