title: Unable to use jinja2 template in pip package created from python module
body: <p>I have a python project with the following directory structure</p>
  
  <pre><code>foo
    |--MANIFEST.in
    |--requirements.txt
    |--setup.py
    |--foo.py
    |--templates/
       |--bar.tmpl
  </code></pre>
  
  <p>where <code>setup.py</code> is a python script. Previously, I was using an install script to symlink the script to my user's private <code>bin</code> (and using it with success), but decided to package it up (first time doing so). I'm able to successfully install the package in a virutalenv using <code>$ pip install .</code> from the project's root directory, and I am able to execute most of the script until I generate a template with <code>jinja2</code>. It seems as though either the <code>templates</code> dir is not getting installed with the rest of the package, or my script is not finding the path to the <code>templates</code> dir correctly.</p>
  
  <p>Excerpt from <code>foo.py</code>:</p>
  
  <pre><code>from jinja2 import Environment, ModuleLoader
  
  def generate_readme(template_file):
      template_env = Environment(loader=PackageLoader('foo','templates'))
      template = template_env.get_template(template_file)        
      template_vars = {"title": get_title()}
      output = template.render(template_vars)
      return output
  </code></pre>
  
  <p><strong>Note</strong>: <code>'bar.tmpl'</code> is passed to this function as <code>template_file</code></p>
  
  <p>Excerpt from <code>setup.py</code>:</p>
  
  <pre><code>from setuptools import setup
  
  setup(name='foo',                                                         
        py_modules=['foo'],
        entry_points={'console_scripts': ['foo = foo:foo']}          
        include_package_data=True,
        zip_safe=False)
  </code></pre>
  
  <p>Contents of <code>MANIFEST.in</code>:</p>
  
  <pre><code>include templates/*
  </code></pre>
  
  <p>Relevant Traceback:</p>
  
  <pre><code>  File "/home/username/.virtualenvs/foo/local/lib/python2.7/site-packages/foo.py", line 30, in generate_readme
  template = template_env.get_template(template_file)
    File "/home/username/.virtualenvs/foo/local/lib/python2.7/site-packages/jinja2/environment.py", line 812, in get_template
  return self._load_template(name, self.make_globals(globals))
    File "/home/username/.virtualenvs/foo/local/lib/python2.7/site-packages/jinja2/environment.py", line 774, in _load_template
  cache_key = self.loader.get_source(self, name)[1]
    File "/home/username/.virtualenvs/foo/local/lib/python2.7/site-packages/jinja2/loaders.py", line 235, in get_source
    raise TemplateNotFound(template)
  jinja2.exceptions.TemplateNotFound: bar.tmpl
  </code></pre>
  
  <p>I have spent a few hours googling, reading similar stackoverflow threads, reading the jinja and setuptools docs, and reading similar code. Everything I have tested just results in the same error message, and I am somewhat at a loss. Any help is greatly appreciated.</p>