Update pins and add a rtd config.

Author: ionelmc

.readthedocs.yml

@@ -0,0 +1,9 @@
+# See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
+version: 2
+sphinx:
+  configuration: docs/conf.py
+formats: all
+python:
+  version: 3
+  install:
+    - requirements: docs/requirements.txt

docs/requirements.txt

@@ -1,4 +1,4 @@
-sphinx==2.3.1
+sphinx==3.0.3
 sphinx-py3doc-enhanced-theme==2.4.0
 docutils==0.16
 -e .

tox.ini

@@ -13,7 +13,7 @@ setenv =
     PYTHONUNBUFFERED=yes
 
     # Use env vars for (optional) pinning of deps.
-    pytest46:  _DEP_PYTEST=pytest==4.6.9
+    pytest46:  _DEP_PYTEST=pytest==4.6.10
     pytest53:  _DEP_PYTEST=pytest==5.3.2
     pytest54:  _DEP_PYTEST=pytest==5.4.2
 
@@ -32,7 +32,7 @@ passenv =
 deps =
     {env:_DEP_PYTEST:pytest}
     {env:_DEP_PYTESTXDIST:pytest-xdist}
-    {env:_DEP_COVERAGE:coverage<5}
+    {env:_DEP_COVERAGE:coverage}
 pip_pre = true
 commands =
     pytest {posargs:-vv}