Add connectorCapabilities global object (loopbackio#179) (loopbackio#182)

Backport of loopbackio#179

Author: superkhau

test/init.js

@@ -52,4 +52,9 @@ global.getDataSource = global.getSchema = function(useUrl) {
   return db;
 };
 
+global.connectorCapabilities = {
+  ilike: false,
+  nilike: false,
+};
+
 global.sinon = require('sinon');