matplotlib import error with python2.7

!!!!!!!!!!!!!!!!!!! Interrupted: 8 errors during collection !!!!!!!!!!!!!!!!!!!!
=========================== 8 error in 2.39 seconds ============================
(compas-dev2) bash-3.2$ clear

(compas-dev2) bash-3.2$ ls
AUTHORS.md      MANIFEST.in     dist            requirements.txt    tasks.py
CHANGELOG.md        README.md       docs            setup.cfg       temp
CONTRIBUTING.md     bin         pytest.ini      setup.py        tests
LICENSE         data            requirements-dev.txt    src
(compas-dev2) bash-3.2$ invoke test
============================= test session starts ==============================
platform darwin -- Python 2.7.15, pytest-4.6.5, py-1.8.0, pluggy-0.13.0
rootdir: /Users/lichen7/WORK/compas, inifile: pytest.ini, testpaths: tests, src
collected 20 items / 8 errors / 12 selected

==================================== ERRORS ====================================
__________ ERROR collecting tests/compas/datastructures/test_mesh.py ___________
tests/compas/datastructures/test_mesh.py:5: in <module>
    from compas.datastructures import Mesh
src/compas/datastructures/__init__.py:150: in <module>
    from .network import *
src/compas/datastructures/network/__init__.py:7: in <module>
    from ._network import *
src/compas/datastructures/network/_network.py:17: in <module>
    from compas.geometry import centroid_points
src/compas/geometry/__init__.py:496: in <module>
    from .isolines import *
src/compas/geometry/isolines/__init__.py:8: in <module>
    from .isolines_numpy import *
src/compas/geometry/isolines/isolines_numpy.py:11: in <module>
    import matplotlib.pyplot as plt
//anaconda3/envs/compas-dev2/lib/python2.7/site-packages/matplotlib/pyplot.py:115: in <module>
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
//anaconda3/envs/compas-dev2/lib/python2.7/site-packages/matplotlib/backends/__init__.py:63: in pylab_setup
    [backend_name], 0)
//anaconda3/envs/compas-dev2/lib/python2.7/site-packages/matplotlib/backends/backend_macosx.py:17: in <module>
    from matplotlib.backends import _macosx
E   RuntimeError: Python is not installed as a framework. The Mac OS X backend will not be able to function correctly if Python is not installed as a framework. See the Python documentation for more information on installing Python as a framework on Mac OS X. Please either reinstall Python as a framework, or try one of the other backends. If you are using (Ana)Conda please install python.app and replace the use of 'python' with 'pythonw'. See 'Working with Matplotlib on OSX' in the Matplotlib FAQ for more information.
Licini / compas

matplotlib import error with python2.7 #10
