[lyon] Also override cluster priority for orion and hercule in generator

data/grid5000/sites/lyon/clusters/hercule/hercule.json

 {
   "created_at": "Tue, 02 Oct 2012 12:00:00 GMT",
-  "priority": "201299",
   "kavlan": true,
   "model": "Dell C6220",
+  "priority": "201299",
   "production": true,
   "type": "cluster",
   "uid": "hercule"

data/grid5000/sites/lyon/clusters/orion/orion.json

 {
   "created_at": "Fri, 14 Sep 2012 12:00:00 GMT",
-  "priority": "201299",
   "kavlan": true,
   "model": "Dell R720",
+  "priority": "201299",
   "production": true,
   "type": "cluster",
   "uid": "orion"

generators/input/sites/lyon/clusters/hercule.rb

@@ -3,6 +3,7 @@ site :lyon do |site_uid|
   cluster :hercule do |cluster_uid|
     model "Dell C6220"
     created_at Time.parse("2012-10-02 12:00 GMT").httpdate
+    priority "201299"
     kavlan true
     production true
 

generators/input/sites/lyon/clusters/orion.rb

@@ -3,6 +3,7 @@ site :lyon do |site_uid|
   cluster :orion do |cluster_uid|
     model "Dell R720"
     created_at Time.parse("2012-09-14 12:00 GMT").httpdate
+    priority "201299"
     kavlan true
     production true