title: Git submodules not updating?
body: <p>I have a project in which I've included some libraries as submodules. They work fine on the machine that you add them on, but when I get home and checkout the repo, I get the folders for the submodules but they are empty.</p>
  
  <p><strong>.gitmodules</strong></p>
  
  <pre><code>Neon@Neon-PC /cygdrive/c/xampp/htdocs/learning-lithium
  $ cat .gitmodules
  [submodule "libraries/lithium"]
          path = libraries/lithium
          url = git://github.com/UnionOfRAD/lithium.git
  [submodule "app/webroot/css/elements"]
          path = app/webroot/css/elements
          url = https://github.com/dmitryf/elements.git
  [submodule "app/libraries/li3_markdown"]
          path = app/libraries/li3_markdown
          url = https://github.com/sandelius/li3_markdown.git
  [submodule "app/webroot/markitup"]
          path = app/webroot/markitup
          url = https://github.com/markitup/1.x.git
  </code></pre>
  
  <p><strong>Config and status commands</strong>  </p>
  
  <pre><code>Neon@Neon-PC /cygdrive/c/xampp/htdocs/learning-lithium
  $ git submodule
  -af14f48b419310935446176290e1f9dc641400e0 app/libraries/li3_markdown
  -ebdcd8ca09c874f5e2ef81ec198cc441f37a4f74 app/webroot/css/elements
  -328291e49a3c7e1fb76b3342f112734864836205 app/webroot/markitup
  -4980010526d05c556c496ff63951da31828c5943 libraries/lithium
  
  Neon@Neon-PC /cygdrive/c/xampp/htdocs/learning-lithium
  $ git submodule update
  
  Neon@Neon-PC /cygdrive/c/xampp/htdocs/learning-lithium
  $ git submodule status
  -af14f48b419310935446176290e1f9dc641400e0 app/libraries/li3_markdown
  -ebdcd8ca09c874f5e2ef81ec198cc441f37a4f74 app/webroot/css/elements
  -328291e49a3c7e1fb76b3342f112734864836205 app/webroot/markitup
  -4980010526d05c556c496ff63951da31828c5943 libraries/lithium
  </code></pre>
  
  <p>I added these as you would normally with,<br>
  <code>git submodule add &lt;repo&gt; &lt;path&gt;</code><br>
  <code>git submodule init</code></p>
  
  <p>The submodules are hosted on Github and my repo is hosted on Bitbucket, although I'm not sure if this is relevant.</p>