Be more cautious when testing for OpenLayers
Enable travis.
Add build status to README.md
Merge pull request #215 from chrismayer/master

Be more cautious when testing for OpenLayers
Merge pull request #216 from marcjansen/travis

Enable travis. (r=@bartvde)
Smaller formatting changes to README.md
Better formatting and headless testing.
Minors

We use OpenLayers 2.13.1