Minor fixups in etcd discovery blog post.

content/blog/2015-08-17-service-discovery-with-etcd.md

@@ -47,8 +47,8 @@ look like this:
 
 ```
 {
-  Targets: ["10.0.33.1:54423", "10.0.34.12:32535"],
-  Labels: {
+  "targets": ["10.0.33.1:54423", "10.0.34.12:32535"],
+  "labels": {
     "job": "node_exporter"
   }
 }
@@ -161,7 +161,7 @@ instance or entire service disappears however, we call `srvs.handle` using the
 We finish each update by another call to `srvs.persist` to write out the
 changes to the file Promtheus is watching.
 
-### Modifcation methods
+### Modification methods
 
 So far so good – conceptually this works. What remains are the `update` and
 `delete` handler methods as well as the `persist` method.