added 'requirements_test' with the additional packages necessary to run the tests
added root package 'tests'
Update .travis.yml: set 'script' which will execute the test suite
added tests covering import of 'vidle', 'vis', 'visual' and 'visual_common'
Update .travis.yml: added the installation steps for 'wxPython'
partially reverted e70992d
Update .travis.yml: fixed the patching of wxPython 2.9.4.0
Update .travis.yml: added a requirement of 'wxPython'
Update .travis.yml: added a requirement of 'wxPython'
Merge pull request #30 from glarrain/test_suite

Basic test suite
Merge pull request #31 from glarrain/travis_wxpython

Update .travis.yml: added the installation steps for 'wxPython'
Update .travis.yml: fixed CWD before installation begins
Merge pull request #32 from glarrain/travis_wxpython

Update .travis.yml: fixed CWD before installation begins