add require 'magento/version'

I don't know why this makes it work for me, or conversely why it's not broken for others.


__Current master branch:__

```
$ bundle update
Updating git://github.com/ddollar/foreman.git
Fetching git://github.com/prairie/magnetize.git
remote: Counting objects: 216, done.
remote: Compressing objects: 100% (103/103), done.
remote: Total 216 (delta 76), reused 215 (delta 75)
Receiving objects: 100% (216/216), 23.49 KiB, done.
Resolving deltas: 100% (76/76), done.
Fetching gem metadata from https://rubygems.org/........
Fetching gem metadata from https://rubygems.org/..
Resolving dependencies...
Using archive-tar-minitar (0.5.2) 
Using highline (1.6.18) 
Using net-ssh (2.6.7) 
Using net-scp (1.1.0) 
Using net-sftp (2.1.1) 
Using net-ssh-gateway (1.2.0) 
Using capistrano (2.15.3) 
Using erubis (2.7.0) 
Using json (1.7.7) 
Using mixlib-log (1.6.0) 
Using mixlib-authentication (1.3.0) 
Using mixlib-cli (1.3.0) 
Using mixlib-config (1.1.2) 
Using mixlib-shellout (1.1.0) 
Using net-ssh-multi (1.1) 
Using ipaddress (0.8.0) 
Using systemu (2.5.2) 
Using yajl-ruby (1.1.0) 
Using ohai (6.16.0) 
Using mime-types (1.23) 
Using rest-client (1.6.7) 
Using chef (11.4.4) 
Using dotenv (0.7.0) 
Using thor (0.18.1) 
Using foreman (0.63.0) from git://github.com/ddollar/foreman.git (at master) 
Using gli (2.5.6) 
Using librarian (0.1.0) 
Using librarian-chef (0.0.1) 
Using magnetize (1.0.2) from git://github.com/prairie/magnetize.git (at master) 
Using bundler (1.3.4) 
Your bundle is updated!
```

then: 

```
$ bundle exec magnetize --version
/Users/rjocoleman/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/bundler/gems/magnetize-ffc2fafb6e9e/bin/magnetize:11:in `<top (required)>': uninitialized constant Magnetize::VERSION (NameError)
	from /Users/rjocoleman/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/bin/magnetize:23:in `load'
	from /Users/rjocoleman/.rbenv/versions/2.0.0-p0/lib/ruby/gems/2.0.0/bin/magnetize:23:in `<main>'
```

__Change to this branch__

```
$ bundle update
Updating git://github.com/ddollar/foreman.git
Updating git://github.com/prairie/magnetize.git
Fetching gem metadata from https://rubygems.org/........
Fetching gem metadata from https://rubygems.org/..
Resolving dependencies...
Using archive-tar-minitar (0.5.2) 
Using highline (1.6.18) 
Using net-ssh (2.6.7) 
Using net-scp (1.1.0) 
Using net-sftp (2.1.1) 
Using net-ssh-gateway (1.2.0) 
Using capistrano (2.15.3) 
Using erubis (2.7.0) 
Using json (1.7.7) 
Using mixlib-log (1.6.0) 
Using mixlib-authentication (1.3.0) 
Using mixlib-cli (1.3.0) 
Using mixlib-config (1.1.2) 
Using mixlib-shellout (1.1.0) 
Using net-ssh-multi (1.1) 
Using ipaddress (0.8.0) 
Using systemu (2.5.2) 
Using yajl-ruby (1.1.0) 
Using ohai (6.16.0) 
Using mime-types (1.23) 
Using rest-client (1.6.7) 
Using chef (11.4.4) 
Using dotenv (0.7.0) 
Using thor (0.18.1) 
Using foreman (0.63.0) from git://github.com/ddollar/foreman.git (at master) 
Using gli (2.5.6) 
Using librarian (0.1.0) 
Using librarian-chef (0.0.1) 
Using magnetize (1.0.2) from git://github.com/prairie/magnetize.git (at version) 
Using bundler (1.3.4) 
Your bundle is updated!
```

then:

```
$ bundle exec magnetize --version
NAME
    magnetize - A command-line interface for Magento.

SYNOPSIS
    magnetize [global options] command [command options] [arguments...]

VERSION
    1.0.2

GLOBAL OPTIONS
    --help    - Show this message
    --version - 

COMMANDS
    configure - configure Magento
    help      - Shows a list of commands or help for one command
```