Add tests so that issues #41 and #43 don't occur again

[lizgzil]

Issue #41 occurred when a Title field was never created. We fixed this so that it'll always be created, but we should perform a test to check that this is the case.

In issue #43 we had a situation where no reference components were outputted but then the code tried to predict references for them. Again, we should perform a test so that this situation is checked.

[jdu]

Is this still relevant?

[lizgzil]

hm I don't know. We still have title = reference['Title'] in fuzzy_match_refs.py, which may become an issue. I think my fix to this (which just made sure Title was created) in https://github.com/wellcometrust/reach/pull/42/files changes a file that doesnt exist anymore.

The second problem I think should have been accounted for in the new deep reference parser.

Perhaps worth double checking once the deep ref parser is all in place and working? Any thoughts @ivyleavedtoadflax ?

[kristinenielsen]

@ivyleavedtoadflax any thoughts on this? if not relevant anymore, you can close