README: bin/moss location is incorrect

[ahughes6]

The README states that the file structure to store the MOSS binary should be:

code/
    bin/
        moss

however pymoss looks within its own directory for the bin folder, so either the code needs to fixed to look for code/bin/moss or the directory structure in the README should be:

code/
    pymoss/
        bin/
            moss

The culprit for this is in code/pymoss/runner.py on line 12:

BINARY = os.path.realpath(os.path.join(os.path.dirname(__file__), "bin", "moss"))

which appends bin/moss to the directory /path/to/tmoss/code/pymoss/