[COMMON] Add and run pre-commit linters via tox

- create a .pre-commit-config.yaml configuration file with
  * gitlint
  * trailing blanks linter
  * tabs removal linter
    - exclude .git folder from it
    - exclude Makefiles since tabs are mandatory by default in them
- create a tox pre-commit profile to run it from tox
  note gitlint is not runnable at this pre-commit stage
- create pre-commit-install and pre-commit-uninstall tox profiles to
  (un)install hooks locally and (un)perform tests at each "git commit"
  call (i.e. without calling manually the pre-commit tox profile)
- precise pre-commit stages/types in the pre-commit configuration file
  so that hooks are installed correctly. This avoids messages about
  skipped tests when they are run at a wrong stage.

Issue-ID: OOM-2643
Signed-off-by: guillaume.lambert <guillaume.lambert@orange.com>
Change-Id: Ie95bb4f6f90be80b05a1398973caffeff7936881
diff --git a/kubernetes/log/components/log-logstash/resources/config/onap-pipeline.conf b/kubernetes/log/components/log-logstash/resources/config/onap-pipeline.conf
index d6b0696..b224bf3 100644
--- a/kubernetes/log/components/log-logstash/resources/config/onap-pipeline.conf
+++ b/kubernetes/log/components/log-logstash/resources/config/onap-pipeline.conf
@@ -92,14 +92,14 @@
        if event.get("[mdcname]")
          $num = event.get("[mdcname]").length
        end
-	   if $num != 0
+       if $num != 0
         until $i > $num do
          if event.get("[mdcname]").at($i) and event.get("[mdcvalue]").at($i)
             event.set(event.get("[mdcname]").at($i), event.get("[mdcvalue]").at($i))
          end
          $i=$i+1
         end
-	   end
+       end
           '
     }
 
@@ -151,7 +151,7 @@
     gsub => [
       'message', ' = ', '=',
       'message', '= ', '=null',
-      'message', '=\t', '=null	', #This null is followed by a tab
+      'message', '=\t', '=null\t', #This null is followed by a tab
       'message', '\t$', '\t'
     ]
   }