Add three StorPool API access config options

Add the 'sp-api-http-host', 'sp-api-http-port', and 'sp-auth-token'
config options. The StorPool Cinder backend driver will read them from
the Cinder configuration if specified, so that there is no need for the
/etc/storpool.conf file to exist.

Change-Id: I04669408c789ad3a337edfbc52f54d0bd59238c1
diff --git a/config.yaml b/config.yaml
index 09a0cde..df9d2c3 100644
--- a/config.yaml
+++ b/config.yaml
@@ -48,3 +48,18 @@
       globally, as a default value for Cinder volumes. There is no
       default value for this option; the administrator needs to provide
       an explicit template name.
+  sp-api-http-host:
+    type: string
+    default:
+    description: |
+      The IP address on which the StorPool API is available.
+  sp-api-http-port:
+    type: int
+    default: 81
+    description: |
+      The port on which the StorPool API is available.
+  sp-auth-token:
+    type: string
+    default:
+    description: |
+      Authentication token for the StorPool API.