Download the binary from here
cd ~/Downloads # cd to where you downloaded the file to
chmod +x fakecas # Make the server executable
./fakecas # Run the server
./fakecas -h # Print possible configuration options
# Usage of ./fakecas:
# -dbaddress="localhost:27017": The address of your mongodb. ie: localhost:27017
# -dbname="osf20130903": The name of your OSF database
# -host="localhost:8080": The host to bind to
# -osfhost="localhost:5000": The osf host to bind to