Set Python and Ubuntu versions in .readthedocs.yaml

It now follows the ONAP gate configurations.
It also fixes the settings and formats it.

Issue-ID: DOC-811
Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
Change-Id: I806f6204f0f44d6f79ef4c1552c5659f0f59faf7
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 3797dc8..f56b3b7 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -3,18 +3,16 @@
 # Read the Docs configuration file
 # See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
 # Required
+
 version: 2
-
-formats:
-  - htmlzip
-
 build:
-  image: latest
+  os: ubuntu-20.04
+  tools:
+    python: "3.8"
 
 python:
-  version: 3.7
   install:
-    - requirements: docs/requirements-docs.txt
+  - requirements: docs/requirements-docs.txt
 
 sphinx:
   configuration: docs/conf.py
diff --git a/docs/tox.ini b/docs/tox.ini
index 4bbc640..9d0f3ee 100644
--- a/docs/tox.ini
+++ b/docs/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 minversion = 1.6
-envlist = docs,
+envlist = docs,docs-linkcheck,docs-spellcheck
 skipsdist = true
 
 [testenv:docs]
@@ -8,21 +8,18 @@
 deps =
     -r{toxinidir}/requirements-docs.txt
     -chttps://raw.githubusercontent.com/openstack/requirements/stable/yoga/upper-constraints.txt
-    -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt
+    -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt?h=master
 commands =
-    sphinx-build -b html -n -d {envtmpdir}/doctrees ./ {toxinidir}/_build/html
-    echo "Generated docs available in {toxinidir}/_build/html"
-whitelist_externals =
-    echo
-    git
-    sh
+    sphinx-build -q -b html -n -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/html
 
 [testenv:docs-linkcheck]
 basepython = python3.8
-#deps = -r{toxinidir}/requirements-docs.txt
-commands = echo "Link Checking not enforced"
-#commands = sphinx-build -b linkcheck -d {envtmpdir}/doctrees ./ {toxinidir}/_build/linkcheck
-whitelist_externals = echo
+deps =
+    -r{toxinidir}/requirements-docs.txt
+    -chttps://raw.githubusercontent.com/openstack/requirements/stable/yoga/upper-constraints.txt
+    -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt?h=master
+commands =
+    sphinx-build -q -b linkcheck -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/linkcheck
 
 [testenv:docs-spellcheck]
 basepython = python3.8
@@ -31,4 +28,4 @@
     -chttps://raw.githubusercontent.com/openstack/requirements/stable/yoga/upper-constraints.txt
     -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt?h=master
 commands =
-    sphinx-build -W -q -b spelling -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/spellcheck
+    sphinx-build -q -b spelling -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/spellcheck