Add note to examples about installing API plugin

examples/api/api.js

@@ -2,6 +2,8 @@
 
 var Cylon = require("../..");
 
+// ensure you install the API plugin first:
+// $ npm install cylon-api-http
 Cylon.api({
   host: "0.0.0.0",
   port: "8080"

examples/api/api.markdown

@@ -13,6 +13,8 @@ First, let's import Cylon:
 Next up, we'll configure the API Cylon will serve, telling it to serve on port
 `8080`.
 
+    // ensure you install the API plugin first:
+    // $ npm install cylon-api-http
     Cylon.api({
       host: '0.0.0.0',
       port: '8080'

examples/hello/fluent-hello.js

@@ -2,6 +2,8 @@
 
 var Cylon = require("../..");
 
+// ensure you install the API plugin first:
+// $ npm install cylon-api-http
 Cylon.api();
 
 Cylon

examples/hello/hello.js

@@ -2,6 +2,8 @@
 
 var Cylon = require("../..");
 
+// ensure you install the API plugin first:
+// $ npm install cylon-api-http
 Cylon.api();
 
 Cylon.robot({

examples/robot_commands/robot_commands.js

@@ -2,6 +2,8 @@
 
 var Cylon = require("../..");
 
+// ensure you install the API plugin first:
+// $ npm install cylon-api-http
 Cylon.api();
 
 Cylon.robot({

examples/robot_commands/robot_commands.markdown

@@ -16,6 +16,8 @@ First, let's make sure to load up Cylon:
 
 Now that we've got that, let's set up the api:
 
+    // ensure you install the API plugin first:
+    // $ npm install cylon-api-http
     Cylon.api();
 
 And with that done let's define our robot:

examples/sphero-pebble-sf/sphero-pebble-sf.js

@@ -2,6 +2,8 @@
 
 var Cylon = require("../..");
 
+// ensure you install the API plugin first:
+// $ npm install cylon-api-http
 Cylon.api({ host: "0.0.0.0", port: "8080" });
 
 Cylon.robot({

examples/sphero-pebble-sf/sphero-pebble-sf.markdown

@@ -7,6 +7,8 @@ First, let's import Cylon:
 Next up, we'll configure the API Cylon will serve, telling it to serve on port
 `8080`.
 
+    // ensure you install the API plugin first:
+    // $ npm install cylon-api-http
     Cylon.api({ host: '0.0.0.0', port: '8080' });
 
 Now that we have Cylon imported, we can start defining our Pebble robot: