title: Django-pipeline 'compressed' is not a valid tag library: ImportError raised loading pipeline.templatetags.compressed: No module named conf
body: <p>I'm getting this error and I have no clue why suddenly I'm having issue with django-pipeline.</p>
  
  <p>I'm running the project under a virtualenv and I've tried to create a new one with the basic app required to see if it would fix it but I always get this error:</p>
  
  <pre><code>TemplateSyntaxError at /
  'compressed' is not a valid tag library: ImportError raised loading pipeline.templatetags.compressed: No module named conf
  Request Method: GET
  Request URL:    http://127.0.0.1:8000/
  Django Version: 1.7.3
  Exception Type: TemplateSyntaxError
  Exception Value:    
  'compressed' is not a valid tag library: ImportError raised loading pipeline.templatetags.compressed: No module named conf
  Exception Location: /home/ymorin007/.virtualenvs/humor15b/local/lib/python2.7/site-packages/django/template/defaulttags.py in load, line 1119
  Python Executable:  /home/ymorin007/.virtualenvs/humor15b/bin/python
  Python Version: 2.7.6
  Python Path:    
  ['/home/ymorin007/workspace/sites/humor15.com/src',
   '/home/ymorin007/.virtualenvs/humor15b/lib/python2.7',
   '/home/ymorin007/.virtualenvs/humor15b/lib/python2.7/plat-x86_64-linux-gnu',
   '/home/ymorin007/.virtualenvs/humor15b/lib/python2.7/lib-tk',
   '/home/ymorin007/.virtualenvs/humor15b/lib/python2.7/lib-old',
   '/home/ymorin007/.virtualenvs/humor15b/lib/python2.7/lib-dynload',
   '/usr/lib/python2.7',
   '/usr/lib/python2.7/plat-x86_64-linux-gnu',
   '/usr/lib/python2.7/lib-tk',
   '/home/ymorin007/.virtualenvs/humor15b/local/lib/python2.7/site-packages']
  </code></pre>
  
  <p>my setting file</p>
  
  <pre><code>########## COMPRESSION CONFIGURATION
  STATICFILES_STORAGE = 'pipeline.storage.PipelineStorage'
  
  PIPELINE_COMPILERS = (
      'pipeline.compilers.less.LessCompiler',
  )
  
  PIPELINE_CSS = {
      'humor15': {
          'source_filenames': (
              'css/bootstrap.min.css',
              'css/base.css',
              'users/css/base.css',
              'signin/css/base.css',
              'css/media.css',
          ),
          'output_filename': 'css/humor15.css',
          'extra_context': {
              'media': 'screen,projection',
          },
      },
  }
  
  PIPELINE_JS = {
      'humor15': {
          'source_filenames': (
              'js/bootstap.min.js',
          ),
          'output_filename': 'js/humor15.js',
      }
  }
  
  ########## END COMPRESSION CONFIGURATION
  
  THIRD_PARTY_APPS = (
      'ckeditor',  # https://github.com/shaunsephton/django-ckeditor#installation
      'crispy_forms',
      'django_countries',  # https://pypi.python.org/pypi/django-countries http://en.wikipedia.org/wiki/ISO_3166-1
      'django_mobile',
      'pipeline',
      'social.apps.django_app.default',  # http://psa.matiasaguirre.net/
  )
  
  INSTALLED_APPS = DJANGO_APPS + HUMOR15_APPS + THIRD_PARTY_APPS + LOCAL_APPS
  </code></pre>