update for latest sphinx rtd theme release (#1368)

* update for latest sphinx rtd theme release

* Update conf.py

Author: alex

doc/conf.py

@@ -15,8 +15,6 @@
 import re
 import sys
 
-import sphinx_rtd_theme
-
 HERE = os.path.abspath(os.path.dirname(__file__))
 
 
@@ -132,7 +130,6 @@ def find_version(*file_paths):
     html_context["READTHEDOCS"] = True
 
 html_theme = "sphinx_rtd_theme"
-html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the