Add the dependencies for the QA dashboard to the shared stack. These are listed in this environment file here: https://github.com/Quansight/lsst_dashboard/blob/master/environment.yml

Packages in that file for documentation (e.g., sphinx, nbsite, recommonmark, and sphinx_rtd_theme) are not required, and the only specific version requirement we are aware of is panel >= 0.6.3.