groundFungus:
I think that the first thing is run the I2C scanner. It does no good to try anything else until we know it is communicating.
The scanner shows one device with address 0x0D.
As jremington writes, it turns out that I don't have the HMC5883L. Apparently I have a QMC5883L. There are a couple of libraries out there and some people report success with the library found in this post on reddit.
I tried this and it's now working. Well, it's giving values that change. I still have to work out what it's telling me 
Thank you