travis updated

Author: tawabshakeel

.travis.yml

@@ -1,4 +1,4 @@
-language: python            # this works for Linux but is an error on macOS or Windows
+language: python   # this works for Linux but is an error on macOS or Windows
 python:
   - "3.6"      # current default Python on Travis CI
   - "3.7"
@@ -10,17 +10,10 @@ jobs:
       os: osx
       osx_image: xcode11.2  # Python 3.7.4 running on macOS 10.14.4
       language: shell       # 'language: python' is an error on Travis CI macOS
-    - name: "Python 3.6.0 on Windows"
-      os: windows           # Windows 10.0.17134 N/A Build 17134
-      language: shell       # 'language: python' is an error on Travis CI Windows
-      before_install:
-        - choco install python --version 3.6.0
-        - python -m pip install --upgrade pip
-      env: PATH=/c/Python36:/c/Python36/Scripts:$PATH
 install:
   - pip3 install --upgrade pip  # all three OSes agree about 'pip3'
-  - pip3 install -r requirements.txt
-  - pip3 install explainx
+  - pip install -r requirements.txt
+  - pip install explainx
 
 # 'python' points to Python 2.7 on macOS but points to Python 3.8 on Linux and Windows
 # 'python3' is a 'command not found' error on Windows but 'py' works on Windows only