Added a venv

Author: gavin-aguiar

eng/templates/jobs/build.yml

@@ -10,8 +10,10 @@ jobs:
           python --version
         displayName: 'Check python version'
       - bash: |
+           python -m venv .env
+          .env\Scripts\Activate.ps1
           python -m pip install -U pip
           python -m pip install .
-          pip install twine wheel
+          python -m pip install twine wheel
           python setup.py sdist bdist_wheel
         displayName: 'Build Python SDK'