Make running test_wps_parameters.py more flexible

[eyvorchuk]

Currently, the file paths inside sample_parameter_config.cfg are relative to the osprey root directory. This makes it so that running the test only succeeds if run from this root directory. In order to allow it so that the test can be run from anywhere, a temporary config file should be written at run time to contain the absolute paths using os.path.abspath and resource_filename and to be passed into wps_parameters.