Chainable/fluent configure methods (#544)

* Make chaining available in Stargazers

Allows for:

```php
$stargazers = $client->repo()->stargazers()->configure('star')->all('vuejs', 'vue');
```

instead of

```php
$stargazers = $client->repo()->stargazers();
$stargazers->configure('star');
$stargazers = $stargazers->all('vuejs', 'vue');
```

* Make all configure methods chainable

Author: acrobat

lib/Github/Api/GitData/Blobs.php

@@ -19,12 +19,16 @@ class Blobs extends AbstractApi
      * Configure the Accept header depending on the blob type.
      *
      * @param string|null $bodyType
+     *
+     * @return self
      */
     public function configure($bodyType = null)
     {
         if ('raw' === $bodyType) {
             $this->acceptHeaderValue = sprintf('application/vnd.github.%s.raw', $this->client->getApiVersion());
         }
+
+        return $this;
     }
 
     /**

lib/Github/Api/Issue/Comments.php

@@ -20,6 +20,8 @@ class Comments extends AbstractApi
      *
      * @link https://developer.github.com/v3/issues/comments/#custom-media-types
      * @param string|null $bodyType
+     *
+     * @return self
      */
     public function configure($bodyType = null)
     {
@@ -28,6 +30,8 @@ public function configure($bodyType = null)
         }
 
         $this->acceptHeaderValue = sprintf('application/vnd.github.%s.%s+json', $this->client->getApiVersion(), $bodyType);
+
+        return $this;
     }
 
     /**

lib/Github/Api/Project/AbstractProjectApi.php

@@ -13,10 +13,14 @@ abstract class AbstractProjectApi extends AbstractApi
      * Configure the accept header for Early Access to the projects api
      *
      * @see https://developer.github.com/v3/repos/projects/#projects
+     *
+     * @return self
      */
     public function configure()
     {
         $this->acceptHeaderValue = 'application/vnd.github.inertia-preview+json';
+
+        return $this;
     }
 
     public function show($id, array $params = array())

lib/Github/Api/Project/Cards.php

@@ -14,10 +14,14 @@ class Cards extends AbstractApi
      * Configure the accept header for Early Access to the projects api
      *
      * @see https://developer.github.com/v3/repos/projects/#projects
+     *
+     * @return self
      */
     public function configure()
     {
         $this->acceptHeaderValue = 'application/vnd.github.inertia-preview+json';
+
+        return $this;
     }
 
     public function all($columnId, array $params = array())

lib/Github/Api/Project/Columns.php

@@ -14,10 +14,14 @@ class Columns extends AbstractApi
      * Configure the accept header for Early Access to the projects api
      *
      * @see https://developer.github.com/v3/repos/projects/#projects
+     *
+     * return self
      */
     public function configure()
     {
         $this->acceptHeaderValue = 'application/vnd.github.inertia-preview+json';
+
+        return $this;
     }
 
     public function all($projectId, array $params = array())

lib/Github/Api/Repository/Comments.php

@@ -15,6 +15,11 @@ class Comments extends AbstractApi
 {
     use AcceptHeaderTrait;
 
+    /**
+     * @param string|null $bodyType
+     *
+     * @return self
+     */
     public function configure($bodyType = null)
     {
         switch ($bodyType) {
@@ -35,6 +40,8 @@ public function configure($bodyType = null)
         }
 
         $this->acceptHeaderValue = $header;
+
+        return $this;
     }
 
     public function all($username, $repository, $sha = null)

lib/Github/Api/Repository/Stargazers.php

@@ -20,12 +20,16 @@ class Stargazers extends AbstractApi
      * @see https://developer.github.com/v3/activity/starring/#alternative-response-with-star-creation-timestamps
      *
      * @param string $bodyType
+     *
+     * @return self
      */
     public function configure($bodyType = null)
     {
         if ('star' === $bodyType) {
             $this->acceptHeaderValue = sprintf('application/vnd.github.%s.star+json', $this->client->getApiVersion());
         }
+
+        return $this;
     }
 
     public function all($username, $repository)