Add windows CI (failing)(#82)

Author: hmacdope

.github/workflows/build.yml

@@ -17,7 +17,7 @@ jobs:
       max-parallel: 12
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest]
+        os: [ubuntu-latest, macos-latest, windows-latest]
         python-version: ['3.6', '3.7', '3.8']
 
     steps:
@@ -30,7 +30,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         python -m pip install  pytest 
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        pip install -r requirements.txt
     - name: Install Pytng
       run: |
         python setup.py install