Release 0.1

This release labels the very first release of this plugin.
At this point, it is basically a re-implementation of Chris Toomeys
plugin: vim-tmux-runner [1]. However, in contrast to his plugin, this
one uses tmux's pane IDs (which are created uniquely per tmux session)
rather than the volatile pane indices. This makes the plugin
considerably more stable.

Note: Future development will probably remove some of the currently
existing functionality. If you would like a drop-in replacement for VTR
use this release.

[1] https://github.com/christoomey/vim-tmux-runner