Add species synonyms

[emillipede]

for new changes, please submit all pull requests to the test-circleci branch

addresses #95

Motivation and context

SM's current tree inventory dataset uses some outdated species names. SM's arborist recognizes Cal Poly's selectree as the authoritative list of current plant botanical names. many cities in LA county also use a variety of names to refer to a common set of tree species. we want publictreemap to display the most accurate, up to date species names

What I did

to update our csv, I've used to selectree as my reference. where selectree documents a different name, I've used the selectree species name. in all of those cases, I retain the SM species name in the field sm_botanical_name. where selectree indicates additional species synonyms, I've documented them in the field botanical_synonyms separated by semicolons

the SM dataset also separates members of a single recognized species into two species with unique species IDs. the city dataset includes trees identified as:

• Afrocarpus falcatus (2086) and Afrocarpus gracilior (46). according to selectree, these two names are synonyms for the same species. the accepted species name is Afrocarpus falcatus.
• Ficus microcarpa (330) and Ficus microcarpa 'Nitida' (56). according to selectree, these two names are synonyms for the same species. the accepted species name is Ficus Microcarpa

in these two cases, I'm not sure how to resolve the issue. for now, I've left the four rows in tact and listed the selectree-specified species name in the botanical_name field. I don't think this approach is a long term solution. I'd like to incorporate a synonym check into the parser for data from other LA county cities (see #114 and #123)

[emillipede]

@cajaks2 recommended I:

• [x] group all synonyms in a single column separated by semicolons or commas