Abortable Fetch Requests + Fetch Request Queue

- Renamed directory `lib` to `src` to better represent the source files
- fetch_provider.js:
  - Added `maxConcurrency` option, defaults to 5 concurrent requests
  - Added internal vars and helps to aid in the concurrent queue
  - execute() now queues all requests by default, and executes then when able to do so
  - Added provider.areRequestsSaturated() to check if concurrency is maxed out
  - Added signal handling, so fetch requests can be aborted
- query.js: Added options property and setOptions fluent helper (used only by fetch provider atm)
- tests: Updated for proof of coverage of new features
- gulpfile.js: Updated for src rename
- package.json: Added dev dependency abort-controller and updated node-fetch dep to work with signals
- README.md: updated docs

README.md

@@ -85,4 +85,41 @@ With await:
 const res = await api.sessions.create(payload).execute();
 ```
 
+## Aborting requests
+
+When using the FetchProvider, you can provide a controller signal to shutdown a fetch request.
+
+For example:
+
+```js
+
+const controller = new AbortController();
+const signal = controller.signal;
+
+api.organizations.list({}).setOptions({ signal }).execute()
+    .then(res => {
+        // res completed successfully
+        // (this won't fire in this example)
+    })
+    .catch(err => {
+        // request failed or was aborted
+        // in this example, err looks like this:
+        /*
+            err = {
+                statusCode: 503,
+                error: 'The user aborted a request.',
+                message: 'Something went wrong'
+            }
+         */
+    })
+;
+
+// Abort the request
+setTimeout(() => {
+    controller.abort();    
+}, 100);
+
+
+```
+
 See the [Okanjo API documentation](https://developer.okanjo.com/api) for information on what routes are available for use.

dist/client.js

@@ -35,8 +35,8 @@
  * SOFTWARE.
  */
 
-var Provider = require('../lib/provider'),
-    Query = require('../lib/query');
+var Provider = require('../src/provider'),
+    Query = require('../src/query');
 
 /**
  * SDK Base
@@ -65,11 +65,11 @@ function Client(config) {
         // Detect context
         if (process.browser) {
             // Running in browser - default to proxy mode
-            //this.provider = new (require('../lib/providers/jquery_provider'))(this);
-            this.provider = new (require('../lib/providers/fetch_provider'))(this);
+            //this.provider = new (require('../src/providers/jquery_provider'))(this);
+            this.provider = new (require('../src/providers/fetch_provider'))(this);
         } else {
             // Running in Node - Use the HTTP provider by default to make real requests
-            this.provider = new (require('../lib/providers/http_provider'))(this);
+            this.provider = new (require('../src/providers/http_provider'))(this);
         }
     }
 
@@ -82,7 +82,7 @@ function Client(config) {
 /**
  * SDK Version
  */
-Client.Version = '2.6.0';
+Client.Version = '3.0.0';
 
 /**
  * Expose the Provider base class