Merge tag '1.4.0' into develop

Tagged 1.4.0 for release
Start on v1.5 development
Output lots of warnings, but don't stop the story running if there is no $env.json file available
Add link to 'Configuring Storyplayer' in warning message
Merge pull request #65 from datasift/feature/first-run-no-config-should-not-error

Output lots of warnings, but don't stop the story running if there is no...
Merge branch 'release/1.4.1'