gridfs api corrections

index.js

@@ -33,21 +33,21 @@ module.exports = (connectionUri, relaxed) => {
 
             let files_fs = gridfs.createModel({
                 modelName: 'files',
-                mongooseConnection: connection
+                connection: connection
             });
 
             mongoose.files = files_fs;
 
             let testing_fs = gridfs.createModel({
                 modelName: 'testing',
-                mongooseConnection: connection
+                connection: connection
             });
 
             mongoose.testingFiles = testing_fs;
 
             let solution_fs = gridfs.createModel({
                 modelName: 'solution',
-                mongooseConnection: connection
+                connection: connection
             });
 
             mongoose.solutionFiles = solution_fs;