[DOC] Fix some doc8 issues

- move doc8 dependency from docs/requirements-docs.txt to tox.ini
  since it is not needed by other tox profiles
- disable doc8 tox profile voting since linelength issues are not
  completely fixed yet
- fix a few linelength issues

Issue-ID: DOC-765

Signed-off-by: guillaume.lambert <guillaume.lambert@orange.com>
Change-Id: I704fc2ee8087ffbb8a83d693f6dc5a5f7c992b10
diff --git a/docs/oom_setup_kubernetes_rancher.rst b/docs/oom_setup_kubernetes_rancher.rst
index eea46c0..e002d38 100644
--- a/docs/oom_setup_kubernetes_rancher.rst
+++ b/docs/oom_setup_kubernetes_rancher.rst
@@ -276,7 +276,8 @@
 Binaries can be found here for Linux and Mac: https://github.com/rancher/rke/releases/tag/v1.0.6
 
 .. note::
-  There are several ways to install RKE. Further parts of this documentation assumes that you have rke command available.
+  There are several ways to install RKE. Further parts of this documentation
+  assumes that you have rke command available.
   If you don't know how to install RKE you may follow the below steps:
 
   * chmod +x ./rke_linux-amd64