Fix nock request body matching (#961)
Fix nock request body matching (#961)

nock 9.0.19 started enforcing the specified request body
(https://github.com/node-nock/nock/pull/921), so tighten up our tests to
cope with that.
canonical-websites/build.snapcraft.io,canonical-websites/build.snapcraft.io,canonical-ols/build.snapcraft.io,canonical-websites/build.snapcraft.io,canonical-ols/build.snapcraft.io,canonical-ols/build.snapcraft.io