Enter into docker container using GITBash

# find the name of the machine created.
docker-machine ls
docker-machine env --shell cmd <nameOfTheMachine>
docker machine ssh <nameOfTheMachine>

Then 

Use the command docker exec -it <container name> /bin/bash to get a bash shell in the container
Generically, use docker exec -it <container name> <command> to execute whatever command you