Bash script to install vim configuration files
Shebang

You should declare what shell you require to make porting the script easy and not a nightmare of commands not being available and syntactical differences leading to bugs.

#!/bin/bash


Pull conflicts

The script does not account for problems when pull does funny things like conflicting. Also to prevent changes to the executable run through PATH modifications (whether intentional or not) you may want to consider using the absolute executable path.

Looping

I'd personally prefer the simpler loop instead of the string looping you do there. 

for i in $dirs
do
  if !(mkdir -p $i) then
    error_exit
  fi
done


at least on my zsh this works as intended.