COPY source files into the docker images

[nims11]

Coming back to HiCAL after a bit. I went through and cleaned out all my old images related to this. I found that I had the same error following the documentation, but if I did 'make clean' in the src directory, then 'make corpus_parser' would work. I suspect there are stale .o objects coming from somewhere.

Originally posted by @isoboroff in #7 (comment)