Removing pypandoc/pandoc requirement

- Was not working well on manylinux2010 build image
- Not necessary, can use markdown directly now

.github/workflows/packagingtest.yml

@@ -17,7 +17,6 @@ jobs:
 
     steps:
     - uses: actions/checkout@v1
-    - uses: r-lib/actions/setup-pandoc@v1
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v1
       with: