Remove reference to Python 2.7 (#1954)

doc/index.rst

@@ -53,7 +53,10 @@ Installation
 |CondaPyViz|_ |CondaDefaults|_ |PyPI|_ |License|_
 
 
-Panel works with `Python 2.7 and Python 3 <https://travis-ci.org/pyviz/panel>`_ on Linux, Windows, or Mac.  The recommended way to install Panel is using the `conda <https://conda.pydata.org/docs/>`_ command provided by `Anaconda <https://docs.continuum.io/anaconda/install>`_ or `Miniconda <https://conda.pydata.org/miniconda.html>`_::
+Panel works with `Python 3 <https://github.com/holoviz/panel/actions?query=workflow%3Apytest>`_ on Linux, Windows, or Mac. The recommended way to install Panel is using the
+`conda <https://docs.conda.io/projects/conda/en/latest/index.html>`_ command provided by
+`Anaconda <https://docs.anaconda.com/anaconda/install/>`_ or
+`Miniconda <https://docs.conda.io/en/latest/miniconda.html>`_::
 
   conda install -c pyviz panel