Add some basic tests
Update Readme, bump version
Add travis CI configuration
Add 'wait for expression to evaluate truthy' option
Enable forwarding of cache headers
Remove debug message
Enable clipping by selector
Add test for forwardCacheHeaders option
Add tests for delay, readyExpression and clipSelector options
noop
Add option to update test baseline images
Propagate test exit code
Allow failed builds on node 0.11 as node-canvas does not build
Merge pull request #1 from alphagov/ready-expression

Add tests and several rendering options