title: git error "could not lock config file .git/config permission denied"
body: <p>I'm developing on aws ec2, and installed git flow.
  And I commanded</p>
  
  <pre><code>git flow init
  </code></pre>
  
  <p>Then, error happened.</p>
  
  <pre><code>Which branch should be used for bringing forth production releases?
     - master
  Branch name for production releases: [master] master
  error: could not lock config file .git/config: permission denied
  Branch name for "next release" development: [develop] 
  error: could not lock config file .git/config: permission denied
  fatal: Unable to create '/var/www/html/dev1/tomato/.git/index.lock': permission denied
  
  How to name your supporting branch prefixes?
  Feature branches? [feature/] 
  error: could not lock config file .git/config: permission denied
  Release branches? [release/] 
  error: could not lock config file .git/config: permission denied
  Hotfix branches? [hotfix/] 
  error: could not lock config file .git/config: permission denied
  Support branches? [support/] 
  error: could not lock config file .git/config: permission denied
  Version tag prefix? [] 
  error: could not lock config file .git/config: permission denied
  </code></pre>
  
  <p>Why I cannot success to git flow init??</p>