uniform tab/spaces in WPS templates

[fmigneault]

Overview

Replaces tabs by spaces to make consistent indents in WPS XML template files and generated responses.

(as per https://github.com/geopython/pywps/blob/master/CONTRIBUTING.rst#contributions-and-licensing)

• I'd like to contribute [feature X|bugfix Y|docs|something else] to PyWPS. I confirm that my contributions to PyWPS will be compatible with the PyWPS license guidelines at the time of contribution.
• I have already previously agreed to the PyWPS Contributions and Licensing Guidelines

[coveralls]

coverage: 84.061%. remained the same
when pulling a929bcf on fmigneault:fix-template-indents
into f646d39 on geopython:main.

[fmigneault]

@cehbrecht FYI

[cehbrecht]

@fmigneault thanks :) Ok to merge?

[fmigneault]

Yes. All good.