Rewrite testing system (#119)

The new test system is written with py.test. These tests are more
comprehensive, run faster by an order of magnitude, and are far more
maintainable. The tests themselves conform to PEP8.

Makefile

@@ -23,6 +23,11 @@ test: bats shellcheck
 parallel:
 	ls test/*bats | time parallel -q -P0 -- docker run --rm -v "$$PWD:/yadm:ro" yadm/testbed bash -c 'bats {}'
 
+.PHONY: pytest
+pytest:
+	@echo Running all pytest tests
+	@pytest -v
+
 .PHONY: bats
 bats:
 	@echo Running all bats tests
@@ -58,3 +63,13 @@ man:
 .PHONY: wide
 wide:
 	man ./yadm.1
+
+.PHONY: sync-clock
+sync-clock:
+	docker run --rm --privileged alpine hwclock -s
+
+.PHONY: .env
+.env:
+	virtualenv --python=python3 .env
+	.env/bin/pip3 install --upgrade pip setuptools
+	.env/bin/pip3 install --upgrade pytest pylint==1.9.2 flake8==3.5.0