make the besancon readers public and add a note about the abandonment of
the BesanconFixed approach
minimalist docs for parse_besancon_model_file
remove failed besancon reader branch (but it will live on in our minds
and our hearts and our shared history!!!  or git log anyway...)
Merge pull request #459 from keflavich/besancon_public_reading

In Besançon page, show example of reading in a table from file
update pip requirements to include specific versions
update setup.py with specific version requirements