Release auto-creation

[roch1990]

At now there is only one way to create release - manual.
Need to add this step to travis.
Travis should create only minor versions.

So, result looks like:

• after merge changes to master travis start to deploy release
• release would be created at https://github.com/roch1990/peon/releases
• release name should consists of version (wildcard - X.Y where X is major version, Y - minor version)
• travis autoincrement minor version of release
• description of release should consists of commit list (with links), chained with this release (deff between previous and current releases)