Reinstated interface tests in main.go since cobbler issue #2846 is fi…

…xed. Also added support for bootloaders in system.go & distro.go.

Merge pull request #1 from cobbler/fix/replace-travis

Replace Travis and update deps

Merge pull request cobbler#8 from wearespindle/feature/fix-ipv6-defau…

…lt-gateway

Fix ipv6_default_gateway field on interface

- Added support for creating kickstart files.

- Added support for creating snippet files.

- Implemented method for setting the nameservers for a system.

- Removed sync call when creating systems. When running this task in isolation
  things would be fine but when running in parallel (creating hundreds or thousands of
  systems at the same time - this is the way Terraform works) Cobbler would start raising
  weird errors. This is due to a race condition problem in Cobbler's source code.
- Implemented method for deleting systems.
- Fixed setting a hostname.

ALPHA release.