Simplify NHD Geometries Based on their Areas

[arottersman]

Overview

NHD RWD Region 2 AOIs range from pretty small (~50sq. km) to 1/4 the size of PA and beyond. Before this PR we had their simplify tolerance at 0.0001 and they were coming back all pixelated. With such many-pointed, larger AOIs we weren't able to run analyze, save celery jobs, etc (see original issue).

Pics

1. Before, Nasty Pixelated -- Can't see Analyze Tabs

2. After (Not the same edge, just an example of clean, clean lines)

_3. Big shape with simplify_tolerance=1000 -- Same shape as 1., but can see Analyze Tabs_

_4. Little shape, simplify_tolerance=50_

Testing Instructions

• Pull this branch
• Pull down the latest https://github.com/WikiWatershed/docker-rwd
• Follow the instructions in #37 to
  • mount the RWD data with Docker Toolbox if you're on a Mac
  • build/run the docker container
• Pull down the latest https://github.com/WikiWatershed/model-my-watershed
• In MMW update localhost on this line to be your docker machine's ip
• Go to localhost:8000 and start selecting some points in the mid-atlantic with Delineate Watershed --> NHD Mid Atlantic Stream Network
• Points near the Delaware will return huge AOIs, elsewhere should return mid-sized ones

Connects #41