lalinference.io (and bayespputils) sets Matplotlib backend to "Template"

Hi @leo-singer, I was wondering if lalinference.io could be completely decoupled from lalinference.bayestar (or just lalinference.bayestar.command) (it looks like it only the rm_f, sqlite_open_r, sqlite_get_filename are required between the two). I've been having Matplotlib backend issues, and have found that it stems from bayespputils importing read_samples from lalinference.io, which all the way down heads to the change of the Matplotlib backend to "Template" in bayestar.command.