Install dependencies for and test build of docutils documentation (#363)

NOTE: I am installing sphinx which also installs docustils rst2html.py tool.
I am installing sphinx and sphinx-rtd-theme in anticipation of testing the
generation of the sphinx-based build of the documentation currently being
worked in #386.

.github/workflows/tribits_testing.yml

@@ -51,6 +51,9 @@ jobs:
         uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.config.python }}
+      -name: Install Python packages
+        run: |
+          pip3 install sphinx sphinx-rtd-theme # For testing doc build
       - name: Version checks
         run: |
           echo "Checking Cmake path and version"

cmake/ctest/github_actions/ctest_github_actions_serial_debug.cmake

@@ -33,7 +33,7 @@ set( EXTRA_CONFIGURE_OPTIONS
   "${enableFortranStr}"
   "-DTriBITS_CTEST_DRIVER_COVERAGE_TESTS=TRUE"
   "-DTriBITS_CTEST_DRIVER_MEMORY_TESTS=TRUE"
-  #"-DTriBITS_ENABLE_DOC_GENERATION_TESTS=ON"
+  "-DTriBITS_ENABLE_DOC_GENERATION_TESTS=ON"
   "-DTriBITS_ENABLE_REAL_GIT_CLONE_TESTS=TRUE"
   "-DTriBITS_TRACE_ADD_TEST=ON"
   "-DTriBITS_SHOW_TEST_START_END_DATE_TIME=ON"