Added a new API: install plugin

Change-Id: I3f8cb4935487cee9b2fa83a0c4d6fa15a53d3b29
diff --git a/core/src/main/java/de/ids_mannheim/korap/constant/OAuth2Scope.java b/core/src/main/java/de/ids_mannheim/korap/constant/OAuth2Scope.java
index ffcf431..915efb5 100644
--- a/core/src/main/java/de/ids_mannheim/korap/constant/OAuth2Scope.java
+++ b/core/src/main/java/de/ids_mannheim/korap/constant/OAuth2Scope.java
@@ -14,6 +14,7 @@
     AUTHORIZE,
     
     LIST_USER_CLIENT,
+    INSTALL_USER_CLIENT,
     
     CLIENT_INFO,
     REGISTER_CLIENT,
diff --git a/core/src/main/java/de/ids_mannheim/korap/exceptions/StatusCodes.java b/core/src/main/java/de/ids_mannheim/korap/exceptions/StatusCodes.java
index 285485d..71e5384 100644
--- a/core/src/main/java/de/ids_mannheim/korap/exceptions/StatusCodes.java
+++ b/core/src/main/java/de/ids_mannheim/korap/exceptions/StatusCodes.java
@@ -148,6 +148,13 @@
     public static final int USER_REAUTHENTICATION_REQUIRED = 1815;
     
     /**
+     * 1850 Plugins
+     */
+
+    public static final int PLUGIN_NOT_PERMITTED = 1850;
+    
+    
+    /**
      * 1900 User account and logins
      */