Fix Vim

One day I updated my MacOS to Sierra, it broke a lot of toolchain on my system.

And the most importantly, VIM is broken.

➜  _posts git:(master) ✗ vim
dyld: Library not loaded: /usr/local/opt/ruby/lib/libruby.2.3.0.dylib
  Referenced from: /usr/local/bin/vim
  Reason: image not found
[1]    6993 abort      vim

Run brew doctor to pinpoint the issue.

➜  _posts git:(master) ✗ brew doctor
Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry and just ignore them. Thanks!
...
.
.
.

Warning: Some installed formula are missing dependencies.
You should `brew install` the missing dependencies:
  brew install libev libsodium udns

Run `brew missing` for more details.
➜  _posts git:(master) ✗ brew install libev libsodium udns
Updating Homebrew...
...
.
.
.

➜  _posts git:(master) ✗ brew upgrade vim
==> Upgrading 1 outdated package, with result:
vim 8.0.0495
...
.
.
.

➜  _posts git:(master) ✗ which vim
/usr/local/bin/vim
➜  _posts git:(master) ✗ vim
➜  _posts git:(master) ✗

Vim got fixed!