Update filepath in readme
Update filepath in readme

Previously, if you changed into `$GOPATH/src/github.com/mop-tracker/mop/cmd/mop` and run any of the make commands you will get an error like `make: *** No targets specified and no makefile found.  Stop.`

running `cd ../..` brings you to `$GOPATH/src/github.com/mop-tracker/mop/` where all of the commands will complete.
mop-tracker/mop,mop-tracker/mop