Removes stale Color-Sampler-Pack plugin

The plugin url has been changed. Instead of updating it though I
choose to remove it as we already have a ton of similar color
schemes committed with this project within the vim-config/.vim/colors
folder and hence this plugin seems unnecessary.
Merge pull request #18 from newcontext/removes_stale_color_sampler

Removes stale Color-Sampler-Pack plugin