Add early fail for `get_normal_newell` when the provided polygon is too small (< 3) #18

	name: Docker Image CI

	on:
	push:
	branches: [ master ]
	pull_request:
	branches: [ master ]

	jobs:

	build:

	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v2
	- name: Build the Docker image
	run: docker build . --file Dockerfile --tag tudelft3d/cjio:latest

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