Create hybrid parser leverage both lattice and network techniques.
Simplify plotting of pdf in lattice case.
Rename "parser.table_bbox" into "parser.table_bbox_parses", since it
represents not a bbox but a dict of bbox to corresponding parsing data.
Still missing: more unit tests, plotting of steps.
Enforce order of textline plotting for unit test consistency in 3.6.
Create wrapper around camelot plot that enforces backwards consistency
with older versions of matplotlib.
No longer rely on the mode but on the parsing analysis during network
detection.
Added unit test for complex table with vertical header and mixed
horizontal / vertical text.
f-strings fail unit tests in Python <3.7, removed them for .format.
Made download_url simulate Mozilla/5.0 to restore unit tests, since
server targetted was 403ing.
Plot takes an optional axes parameter, allowing notebooks more
flexibility.
Header heuristic in hybrid won't include headers which span the
entire table.
Added unit test for issue #132
Fixes https://github.com/camelot-dev/camelot/issues/132
Frh