Update test matrix for Travis CI (drop testing for Python 3.5 and NumPy <1.14)
Update test matrix for Travis CI (drop testing for Python 3.5 and NumPy <1.14)

INM-6/python-neo,NeuralEnsemble/python-neo,apdavison/python-neo,samuelgarcia/python-neo,JuliaSprenger/python-neo