Adding -h to print usage, just to avoid the error message

[nickdgriffin]

Previously "./quickstarh.sh -h" would print an error about it being an invalid parameter and print the usage, now it'll just print the usage.

Also means in future it could have an expanded help if necessary.

[RobertNorthard]

LGTM. Thanks @nickdgriffin.

$ ./quickstart.sh -h
 .....
 .....
Usage:
        ./quickstart.sh 
	    -t local 
	    [-m <MACHINE_NAME>] 
	    [-u <INITIAL_ADMIN_USER>] 
	    [-p <INITIAL_ADMIN_PASSWORD>]

        ./quickstart.sh 
	    -t aws 
	    -m <MACHINE_NAME> 
	    -c <AWS_VPC_ID> 
	    -r <AWS_DEFAULT_REGION> 
	    [-z <AVAILABILITY_ZONE_LETTER>] 
	    [-a <AWS_ACCESS_KEY>] 
	    [-s <AWS_SECRET_ACCESS_KEY>] 
	    [-u <INITIAL_ADMIN_USER>] 
	    [-p <INITIAL_ADMIN_PASSWORD>]