Update test infrastructure. Deprecate Python 2.7.

Author: Eigenstate

.travis.yml

@@ -1,19 +1,17 @@
 language: python
 python:
-    - "2.7"
     - "3.6"
 install:
     - wget https://repo.continuum.io/miniconda/Miniconda-latest-Linux-x86_64.sh -O miniconda.sh;
     - bash miniconda.sh -b -p $HOME/miniconda
     - export PATH="$HOME/miniconda/bin:$PATH"
     - hash -r
     - conda config --set always_yes yes --set changeps1 no
-    - conda config --add channels omnia
     - conda update -q conda
     - conda info -a
     - conda create -q -n test-environment python=$TRAVIS_PYTHON_VERSION pytest numpy
     - conda install ambertools=17 -n test-environment -c http://ambermd.org/downloads/ambertools/conda/
-    - conda install vmd-python networkx psfgen -n test-environment -c conda-forge
+    - conda install vmd-python networkx psfgen parmed -n test-environment -c conda-forge
     - source activate test-environment
     - export AMBERHOME="$HOME/miniconda/envs/test-environment"
     - python setup.py install

setup.py

@@ -32,7 +32,8 @@ def run(self):
       install_requires=["numpy",
                         "networkx>=1.11",
                         "vmd-python>=2.0.4",
-                        "parmed"],
+                        "parmed",
+                        "psfgen"],
       entry_points={
           "console_scripts": [
               "dabble = dabble.__main__:main"