Fix syntax error for bash

Fix this error when using bash (tested with Linux Mint 17 ~ Ubuntu 14.04 trusty):

    $ source ~/.bashrc
    bash: /home/piloupy/.bashrc: line 45: syntax error near unexpected token `{docker'
    bash: /home/piloupy/.bashrc: line 45: `dbu() {docker build -t=$1 .;}'
Merge pull request #3 from samuel-phan/patch-1

Fix syntax error for bash