Add first tests for user
user
```ruby
require './spec/spec_helper'

require './lib/gas'

describe Gas::User do
  it 'should be able to parse name and email from gitconfig format' do
    name = 'Fredrik Wallgren'
    email = 'fredrik.wallgren@gmail.com'
    gitconfig = "[other stuff]\n  foo = bar\n\n[user]\n  name = #{name}\n  email = #{email}\n\n[foo]\n  bar = foo"
    user = Gas::User.parse gitconfig
    user.name.should == name
    user.email.should == email
  end

  it 'should output name and email in the right format' do
    name = 'Fredrik Wallgren'
    email = 'fredrik.wallgren@gmail.com'
    user = Gas::User.new name, email
    user.to_s.should == "[user]\n  name = #{name}\n  email = #{email}"
  end
end
```
assistant