Update docs

Author: m1guelpf

doc/integrations.md renamed to doc/apps.md

@@ -1,24 +1,24 @@
-## Instegrations API
+## Applications API
 [Back to the navigation](README.md)
 
-Wraps [GitHub Integrations API](http://developer.github.com/v3/integrations/).
+Wraps [GitHub Applications API](http://developer.github.com/v3/apps/).
 
 ### Create a new installation token
 For the installation id 123 use the following:
 ```php
-$token = $client->api('integrations')->createInstallationToken(123);
+$token = $client->api('apps')->createInstallationToken(123);
 ```
 
 To create an access token on behalf of a user with id 456 use:
 ```php
-$token = $client->api('integrations')->createInstallationToken(123, 456);
+$token = $client->api('apps')->createInstallationToken(123, 456);
 ```
 
 ### Find all installations
 
-Find all installations for the authenticated integration.
+Find all installations for the authenticated application.
 ```php
-$installations = $client->api('integrations')->findInstallations();
+$installations = $client->api('apps')->findInstallations();
 ```
 
 ### Find installations for a user
@@ -31,7 +31,7 @@ $installations = $client->api('current_user')->installations();
 
 List repositories that are accessible to the authenticated installation.
 ```php
-$repositories = $client->api('integrations')->listRepositories(456);
+$repositories = $client->api('apps')->listRepositories(456);
 ```
 
 ### List repositories for a given installation and user
@@ -43,11 +43,11 @@ $repositories = $client->api('current_user')->repositoriesByInstallation(456);
 ### Add repository to installation
 Add a single repository to an installation.
 ```php
-$client->api('integrations')->addRepository(123);
+$client->api('apps')->addRepository(123);
 ```
 
 ### Remove repository from installation
 Remove a single repository from an installation.
 ```php
-$client->api('integrations')->removeRepository(123);
+$client->api('apps')->removeRepository(123);
 ```