prepared travis & gh-pages, brushed up builds

In order to build the distribution files, follow these steps:
- take a look at the available build steps `gradle tasks` - all arc42 tasks are in one group "arc42-template"
- build projects from golden master `gradle createTemplatesFromGoldenMaster` - remember that you can use shortcuts like `gradle cTFGM` or `gradle createTemplates`
- build different formats `gradle arc42`
- create distribution files (*.zip) `gradle createDistribution`
- distribute files to gh-pages `gradle publishDistribution`