Add Continuous Integration System to Forks

[smcgregor]

Your fork does not run on TravisCI by default so you don't run all the unit tests on every "push".

This can be very confusing. This issue is for helping people setup TravisCI with SauceLabs. Comment if the documentation for continuous integration is not sufficient and you need help. We will then translate any issues or misconceptions into changes in the documentation.

The development guide has details.