Moving the example workflow to the grid - testing

Sourcing the DIRAC environment: You can test the DIRAC environment variables have been set using the echo command. For example:
```
$ echo $DIRAC
/cvmfs/ganga.cern.ch/dirac_ui/
```
If the DIRAC home directory on CVMFS is not listed, the environment variables have not been set correctly.
Generating a DIRAC proxy: You can test if your proxy generation has been successful by using the dirac-proxy-info command.
Successful running of the CERN@school example job: As with the locally-run example, once you have run and retrieved the images from the example job the first frame image should look something like this:

Testing