Migrate to GitHub Actions

[tomkralidis]

Given recent changes in Travis we should make the move to GitHub Actions.

[jodygarnett]

Some notes from migrating core-geonetwork project from travis to github actions:

• it was pretty easy to do (it took hours not days)
• So much faster than Travis
• Have multiple small actions rather than a long script (like we did with Travis previously). This let’s you get feedback faster to folks making a pull-request
• Copy a working example from geonetwork or geoserver

[plant99]

Started working on this, @tomkralidis please assign this to me if someone hasn't already taken this up.

[tomkralidis]

@plant99 thanks for taking this on. Any updates?

[plant99]

Hi @tomkralidis , this branch has some commits, haven't been able to find some time lately to actively take it to completion, please feel free to unassign me from the task, it'd be better if someone else can finish this faster.

edit: the Actions tab in my fork had run a few jobs, please reference that for the current issues with the action.

[tomkralidis]

Progress in #703 (comment) for review/comment.

[tomkralidis]

Implemented first pass in #703. As discussed, we need to add the rest of the test functionality per #703 (comment)

[tomkralidis]

(copying/updating comment #703 (comment) here as part of the issue lineage)

@kalxas @justb4 @francbartoli

FYI GitHub Actions setup passing so far. Here's what is outstanding/not ported from the Travis setup in this PR:

• loading PostgreSQL/PostGIS data
• properly getting the GDAL Python bindings properly installed
• properly getting the pyspatialite dependencies installed
• running any tests that depend on the above
• anything Docker
• building Debian package

I've listed out each test in https://github.com/geopython/pygeoapi/blob/master/.github/workflows/main.yml so as to add/remove accordingly as part of testing. Lines that are commented out need updates/fixes to get CI working properly on those tests. Once all tests pass, then this step will simply be run as pytest.