new read the docs

.readthedocs.yml

@@ -1,6 +1,12 @@
-formats: all
+# Required
+version: 2
+
+# Build documentation in the docs/ directory with Sphinx
+sphinx:
+  configuration: docs/conf.py
 
-requirements_file: requirements.txt
+# Optionally build your docs in additional formats such as PDF and ePub
+formats: all
 
 # Build documentation in the docs/ directory with Sphinx
 sphinx:
@@ -10,7 +16,6 @@ sphinx:
 # docs
 python:
   version: 3.7
-  pip_install: true
   extra_requirements:
     - tests
     - docs