Add Client Credentials Flow as Authentication Method (#330)

Author: lamungu

README.md

@@ -115,7 +115,22 @@ Route::get('/callback', function()
 
 With the Username Password flow, you can directly authenticate with the `Forrest::authenticate()` method.
 
-> To use this authentication you must add your username, and password to the config file. Security token might need to be ammended to your password unless your IP address is whitelisted.
+> To use this authentication you must add your username, and password to the config file. Security token might need to be amended to your password unless your IP address is whitelisted.
+
+```php
+Route::get('/authenticate', function()
+{
+    Forrest::authenticate();
+    return Redirect::to('/');
+});
+```
+
+
+#### Client Credentials authentication flow
+
+With the Client Credentials flow, you can directly authenticate with the `Forrest::authenticate()` method.
+
+> Using this authentication method only requires your consumer secret and key. Your Salesforce Connected app must also have the "Client Credentials Flow" Enabled in its settings.
 
 ```php
 Route::get('/authenticate', function()
@@ -135,7 +150,7 @@ Route::get('/authenticate', function()
 4. Update your config file with values for `loginURL`, `username`, and `password`.
    With the Username Password SOAP flow, you can directly authenticate with the `Forrest::authenticate()` method.
 
-> To use this authentication you can add your username, and password to the config file. Security token might need to be ammended to your password unless your IP address is whitelisted.
+> To use this authentication you can add your username, and password to the config file. Security token might need to be amended to your password unless your IP address is whitelisted.
 
 ```php
 Route::get('/authenticate', function()
@@ -147,7 +162,7 @@ Route::get('/authenticate', function()
 
 If your application requires logging in to salesforce as different users, you can alternatively pass in the login url, username, and password to the `Forrest::authenticateUser()` method.
 
-> Security token might need to be ammended to your password unless your IP address is whitelisted.
+> Security token might need to be amended to your password unless your IP address is whitelisted.
 
 ```php
 Route::Post('/authenticate', function(Request $request)