auto build docs

[mapsam]

Send a request to mapnik/documentation master branch to rebuild on travis-ci, which builds the docs and pushes to the gh-pages branch.

refs: #599

TODO

• land on a commit code for publishing docs - currently set to: [publish docs]
• only run this on master branch builds? - currently the documentation repo itself is just using the master branch to generate docs anyways, so it would be useless to run this command for any other branch.

cc @springmeyer

[mapsam]

Currently unable to actually get this CURL to trigger anything from the command line. Travis responds, though!

{
  "@type": "pending",
  "remaining_requests": 10,
  "repository": {
    "@type": "repository",
    "@href": "/repo/8884379",
    "@representation": "minimal",
    "id": 8884379,
    "name": "documentation",
    "slug": "mapnik/documentation"
  },
  "request": {
    "repository": {
      "id": 60119461,
      "owner_name": "mapnik",
      "name": "documentation"
    },
    "user": {
      "id": 40531
    },
    "message": null,
    "branch": "master",
    "config": {
    }
  },
  "resource_type": "request"
}

[mapsam]

This is ready to rock thanks to some 👀 from @springmeyer. Once this PR is merged:

• update the gh-pages branch in this repo to forward to the new documentation URL
• update URL in repo
• confirm docs are updating with some updates to src/mapnik_map.cpp

[mapsam]

All 🍏 on travis. @BergWerkGIS okay to merge this with appveyor failing? Shouldn't have an effect on the windows builds at all.

[wilhelmberg]

I think we are good to merge.

AppVeyor is failing because it tries to pull down mapnik-win-sdk-v3.0.11-163-g00e5d00-x64-14.0.7z which we do not have.

We have MAPNIK_GIT: v3.0.10 defined in appveyor.yml.

Will investigate where the refernce to v3.0.11-163-g00e5d00 is coming from ...

[wilhelmberg]

ah, found it: 3dba76a
/cc @springmeyer