add CITE tests to GitHub Actions

# Description
Part of [release packaging](https://github.com/geopython/pycsw/wiki/Release-Packaging) includes performing [OGC CITE testing](https://github.com/geopython/pycsw/wiki/OGC-CITE-Compliance). Given pycsw is an OGC Reference Implementation, CITE testing is a critical piece of compliance.

The pycsw CITE testing task is currently manual and time consuming given we run CITE tests against CITE production and beta for both CSW 2.0.2 and 3.0.0. In addition, we usually run CITE tests for Python 2.7 (thereby skipping our other supported Python versions [2.6, 3.4]).

It would be valuable to run CITE testing as part of Travis to ensure we alway pass CITE across different CSW and Python versions.

# Environment

- operating system: all
- Python version: all
- pycsw version: all
- source/distribution
- [x] git clone
- [ ] DebianGIS/UbuntuGIS
- [ ] PyPI
- [ ] zip/tar.gz
- [ ] other (please specify):
- web server
- [x] Apache/mod_wsgi
- [ ] CGI
- [ ] other (please specify):

# Steps to Reproduce
NA
# Additional Information
- the goal here is to run the CITE tests locally as opposed to somehow running them against the CITE services remotely
- there is some automated workflow at https://gist.github.com/tomkralidis/58cb3ff0a383f9579f46 which could help
- CITE has a production and beta infrastructure; we should discuss/decide what we support