Add deactivate method

Author: bradjones1

src/SynapseAdminHttpApi.php

@@ -160,6 +160,16 @@ public function registerUser(string $registrationSharedSecret, string $username,
     return json_decode($response->getBody()->getContents(), TRUE);
   }
 
+  /**
+   * Deactivate a user.
+   * 
+   * @param string $userId
+   *   User ID.
+   */
+  public function deactivateUser(string $userId): void {
+    $this->send('POST', "v1/deactivate/$userId");
+  }
+  
   /**
    * Query user information.
    *