pfaf scraper bugs

[jwnigel]

• [x] Still getting this error sometime although search term works fine in browser: invalid literal for int() with base 10: ' ' ***Hardiness zone fixed this issue. I think it was zones >= 10 throwing error. ***Using float() instead of int() also.

• [x] Height is returning the string 'to' sometimes. I noticed it in Onion and Rosemary.

• [ ] In Habitat (maybe others), remove pfaf references in square brackets [] Example: 'Rich fertile woods and hillsides[43, 82] in deep well-drained soils[229].' (Although maybe this is necessary for liscensing?

• [x] Clean up output in general: Sometimes strings like "perennial" are returned in all caps. Make things consistent.

• [x] Use regex to grab hardiness zones. Current [-1] indexing doesn't work when zones >= 10

• [x] Add pollinators to scraper

• [ ] When scraping varieties like Acer saccharum var nigra, the search string should be 'Acer+saccharum+nigra', without 'var'

• [ ] #32