Removing the reference to the opp.zsh plugin
Edit the vimrc + Fixing loading molokai

- The setting "let background=dark" has overwritten my colorscheme
- With "autowrite" the buffer is saving automatically when I amswitching
  to another buffer
- Changing the runtimepath: I use now environment-variables
  ($VIMRUNTIME,$VIM) to prevent issues when vim is changing the version
  number