Rename securedrop-admin to sdw-admin

[eloquence]

Status

Ready for review

Description of Changes

Resolves #586. Since securedrop-admin is only provisioned via RPM, no make clean changes should be required.

Test plan

• Ensure you're running a SecureDrop Workstation staging or prod install created from an RPM.
• Observe that the securedrop-admin can be successfully run in dom0
• Check out this PR's branch in your dev env.
• Bump the RPM version to 0.4.1 as illustrated in the detached commit f24804a (you can use the ./update-version.sh script in the base of this repo)
• Build a 0.4.1 RPM by running make dom0-rpm and copying that file to dom0.
• Install the 0.4.1 RPM with sudo dnf install <filename>
• Observe that securedrop-admin can no longer be run in dom0
• Observe that you can now access the tool with sdw-admin in dom0
• Observe that sdw-admin --validate still functions as expected

If you have made code changes

• Linter (make flake8) passes in the development environment
• All tests (make test) pass in dom0 of a Qubes install [no impact on test suite]
• This PR adds/removes files, and includes required updates to the packaging logic in MANIFEST.in and rpm-build/SPECS/securedrop-workstation-dom0-config.spec

[eloquence]

Added test plan and successfully stepped through it, declaring this ready to go. This PR bumps the version to 0.4.1 to facilitate update testing. Happy to change this to an RC version string, or to remove the version bump prior to merge (I think changing it to an RC version probably makes sense).

[eloquence]

As discussed in standup this morning, I've removed the version bump commit f24804a from this PR; the reviewer will need to bump the version before building the RPM (updated test plan accordingly).

[kushaldas]

Works as expected.