Add versioning support, fix bug

**Bug fixed**:
 - `conda update conda` conflict, uninstalled setuptools. _Fix_: uninstall then reinstall setuptools before `conda update conda`

**Version support**:
 - Reformatted build matrix to support per-version TF & Keras testing
 - Current commit tests TF 1.14.0 w/ Keras 2.3.0, more support to come

**Other**:
 - Removed `KERAS` flag, as repo isn't meant for `==FALSE`

.travis.yml

@@ -2,12 +2,15 @@ dist: xenial
 language: python
 python:
   - "3.6"
-matrix:
-  include:
-    - python: 3.6
-      env: KERAS="true"
-    - python: 3.6
-      env: KERAS="false"
+env:
+  matrix:
+#     - KERAS_VERSION="2.2.5" TF_VERSION="1.13.1"
+#     - KERAS_VERSION="2.2.5" TF_VERSION="1.14.0"
+    - TF_VERSION="1.14.0"
+#     - TF_VERSION="2.0.0"
+
+#     - KERAS_VERSION="2.3.0" TF_VERSION="1.14.0"
+    # - KERAS_VERSION="2.3.0" TF_VERSION="2.0.0"
 notifications:
   email: false
 
@@ -16,24 +19,35 @@ before_install:
   - sudo apt-get update
   - sudo apt-get -y install python-pip
   - pip install --upgrade pip
-  - pip install --upgrade pip
   - pip install pep8
   - pip install autopep8
-
-install:
   - wget https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O miniconda.sh;
   - bash miniconda.sh -b -p $HOME/miniconda
   - export PATH="$HOME/miniconda/bin:$PATH"
   - conda config --set always_yes yes --set changeps1 no
-  - conda update -q conda
+  - conda install setuptools
+  - conda install conda=4.7.12
+  - conda update --force conda
   - conda info -a
   - conda create -q -n test-environment python=$TRAVIS_PYTHON_VERSION
   - source activate test-environment
   - export LD_LIBRARY_PATH=$HOME/miniconda/envs/test-environment/lib/:$LD_LIBRARY_PATH
   - pip install -r requirements.txt
-  - if [[ $KERAS_BACKEND == "theano" ]]; then pip install theano && conda install mkl mkl-service; fi
   - conda install coveralls
 
+install:
+  - |
+      if [[ -n "$KERAS_VERSION" ]]; then
+          pip install keras=="$KERAS_VERSION";
+      else
+          pip install keras;
+      fi
+      if [[ -n "$TF_VERSION" ]]; then
+          pip install tensorflow=="$TF_VERSION";
+      else
+          pip install tensorflow;
+      fi
+  
 script:
  - ./test.sh
 
@@ -45,8 +59,3 @@ after_success:
 notifications:
   webhooks:
     - https://coveralls.io/webhook
-
-# E127 = continuation line over-indented for visual indent
-# E128 = continuation line under-indented for visual indent
-# E221 = multiple spaces before operator
-# E251 = unexpected spaces around keyword / parameter equals