mock diffpy.utils and add it to docs.txt

Author: cadenmyers13

docs/source/conf.py

@@ -108,6 +108,9 @@
 # directories to ignore when looking for source files.
 exclude_patterns = ["build"]
 
+# Mock imports so API docs render without installing dependencies.
+autodoc_mock_imports = ["diffpy.utils"]
+
 # The reST default role (used for this markup: `text`) to use for all
 # documents.
 # default_role = None

requirements/docs.txt

@@ -3,3 +3,4 @@ sphinx_rtd_theme
 sphinx-copybutton
 doctr
 m2r2
+diffpy.utils