Increase num retries for mongodb connection (for travis builds)
Increase num retries for mongodb connection (for travis builds)

StarfishStorage/mongomock,marcinbarczynski/mongomock,magaman384/mongomock,chartbeat-labs/mongomock,vmalloc/mongomock,akun/mongomock,drorasaf/mongomock,julianhille/mongomock,mdomke/mongomock