title: Wrong file version in requirement package
body: <p>A file seems to be outdated in requirements package <em>synergine-0.0.1.9</em> when environment is build.</p>
  
  <p><em>.travis.yml</em></p>
  
  <pre><code>language: python
  python:
    - "3.4"
  install:
    - "pip install -r tests_requirements.txt --upgrade"
    - "pip install python-coveralls"
  script:
    - coverage run tests.py --rcfile=.coveragerc -v &amp;&amp; coverage report -m &amp;&amp; python3.4 tests.py
  after_success:
    - coveralls
  </code></pre>
  
  <p><strong>tests_requirements.txt</strong></p>
  
  <pre><code>synergine&gt;=0.0.1
  synergine_xyz&gt;=0.0.1
  </code></pre>
  
  <p><strong>travis-ci.org</strong> build log:</p>
  
  <pre><code>[...]
  pip 6.0.7 from /home/travis/virtualenv/python3.4.2/lib/python3.4/site-packages (python 3.4)
  install.1
  
  1.74s $ pip install -r tests_requirements.txt --upgrade
  
  You are using pip version 6.0.7, however version 7.0.3 is available.
  
  You should consider upgrading via the 'pip install --upgrade pip' command.
  
  Collecting synergine&gt;=0.0.1 (from -r tests_requirements.txt (line 1))
  
    Downloading synergine-0.0.1.9.tar.gz
  
      pypandoc not found
  
  Collecting synergine-xyz&gt;=0.0.1 (from -r tests_requirements.txt (line 2))
  
    Downloading synergine_xyz-0.0.1.9.tar.gz
  
  Installing collected packages: synergine-xyz, synergine
  
    Running setup.py install for synergine-xyz
  
    Running setup.py install for synergine
  
      pypandoc not found
  
  Successfully installed synergine-0.0.1.9 synergine-xyz-0.0.1.9
  
  [...]
  
  [...]
  0.31s$ coverage run tests.py --rcfile=.coveragerc -v &amp;&amp; coverage report -m &amp;&amp; python3.4 tests.py
  
  [...]
  
    File "/home/travis/virtualenv/python3.4.2/lib/python3.4/site-packages/synergine/core/simulation/MetaValue.py", line 19, in unset
  
      del (state[subject])
  
  NameError: name 'state' is not defined
  </code></pre>
  
  <p>The <code>synergine/core/simulation/MetaValue.py", line 19, in unset</code> on travis-ci build is:</p>
  
  <pre><code>del (state[subject])
  </code></pre>
  
  <p>If we look <code>synergine/core/simulation/MetaValue.py", line 19, in unset
  </code> available on <a href="https://pypi.python.org/packages/source/s/synergine/synergine-0.0.1.9.tar.gz#md5=84dfad46c5433a7b5a0672b0d8a6ab61" rel="nofollow">pypi</a>:</p>
  
  <pre><code>del(metas[subject])
  </code></pre>
  
  <p>Files are not identicals. Problem is in a travis-ci cache ? How can i fix that ?</p>
  
  <p>Build page available <a href="https://travis-ci.org/buxx/intelligine" rel="nofollow">here</a>.</p>