Pass through extra scheduler config options

This lets users specify params like "relative_priority" without
the operator needing to know about them.

Change-Id: I8a82725e51e8c7172063e0fe944a9ee9f13bada1

zuul_operator/templates/zuul.conf

@@ -10,7 +10,9 @@ server=zuul-gearman
 start=true
 
 [scheduler]
-tenant_config=/etc/zuul/tenant/main.yaml
+{% for key, value in spec.scheduler.items() -%}
+{{ key }}={{ value }}
+{% endfor %}
 
 [database]
 {% for key, value in spec.database.items() -%}

zuul_operator/zuul.py

@@ -64,6 +64,9 @@ class Zuul:
         self.tenant_secret = spec.get('scheduler', {}).\
             get('config', {}).get('secretName')
 
+        self.spec.setdefault('scheduler', {})['tenant_config'] = \
+            '/etc/zuul/tenant/main.yaml'
+
         ex = self.spec.setdefault('executor', {})
 
         self.cert_manager = certmanager.CertManager(