Add additional work on check-package.

check_package/tasks.py

@@ -7,5 +7,5 @@ from invoke import task, run
 def setup_virtualenvs(ctx):
     temp_dir = tempfile.mkdtemp()
     run('virtualenv {}'.format(temp_dir))
-    run('./{}/bin/activate'.format(temp_dir))
-    run('pip install -e .')
+    run('{}/bin/pip install -e .'.format(temp_dir))
+    # TODO: Run tests after the installation.

pyproject.toml

@@ -16,4 +16,4 @@ virtualenv = "^16.0"
 pytest = "^3.0"
 
 [tool.poetry.scripts]
-check-package = 'check_package.main:program'
+'check-package' = 'check_package.main:program.run'