Update continuous integration testing.

Allow linter to fail.
Add pipeline badge to each writeup to make grading easier.

.gitlab-ci.yml

@@ -8,6 +8,7 @@ cache:
 lint:
   tags: [python-ci]
   image: python:3.8-buster
+  allow_failure: true
   script:
     - pip3 -q install flake8 pep8-naming typing
     - python3 -m flake8

control/writeup/README.md

-# Project 3: Control
+# Project 3: Control [![tests](../../../badges/submit-proj3/pipeline.svg)](../../../pipelines/submit-proj3/latest)
 
 Replace this with your own writeup! Please place all figures in this directory.
 

introduction/writeup/README.md

-# Project 1: Introduction
+# Project 1: Introduction [![tests](../../../badges/submit-proj1/pipeline.svg)](../../../pipelines/submit-proj1/latest)
 
 Replace this with your own writeup!

localization/writeup/README.md

-# Project 2: Localization
+# Project 2: Localization [![tests](../../../badges/submit-proj2/pipeline.svg)](../../../pipelines/submit-proj2/latest)
 
 Replace this with your own writeup! Please place all figures in this directory.