Apply updates from cookiecutter

This automated commit applies the latest updates from our cookiecutters [1] to
this repo.

[1]: https://github.com/hypothesis/cookiecutters

Makefile

@@ -23,7 +23,7 @@ dev: python
 .PHONY: shell
 $(call help,make shell,"launch a Python shell in this project's virtualenv")
 shell: python
-	@pyenv exec tox -qe dev --run-command 'ipython'
+	@PYTHONPATH=$(CURDIR) TOX_TESTENV_PASSENV=PYTHONPATH pyenv exec tox -qe dev --run-command 'ipython'
 
 .PHONY: sql
 $(call help,make sql,"Connect to the dev database with a psql shell")

tox.ini

@@ -21,8 +21,6 @@ setenv =
     dev: DATABASE_URL = {env:DATABASE_URL:postgresql://postgres@localhost:5436/postgres}
     tests: DATABASE_URL = {env:UNITTESTS_DATABASE_URL:postgresql://postgres@localhost:5436/report_tests}
     functests: DATABASE_URL = {env:FUNCTESTS_DATABASE_URL:postgresql://postgres@localhost:5436/report_functests}
-    # Make `import report` work in `make shell`.
-    dev: PYTHONPATH = .
     # From .cookiecutter/includes/tox/setenv:
     MB_DB_USER = {env:MB_DB_USER:postgres}
     # As it's Postgres itself that will be contacting these DBs, this will