This should really be 3 atomic commits but I'm short on time.
- Prints a message on clean environment
- Marked tests as network based
- Added helper that matches lines irrespective of order.
This command ensures that all packages installed have all the
requirements they need, and that requirements have compatible
versions. This is useful because pip can install incompatible
dependencies[1], or a user may have manually (un)installed a
package.
[1] https://github.com/pypa/pip/issues/775