Run "git log" under the same user that cloned the repo

[sleinen]

This avoids "fatal: detected dubious ownership in repository" errors that cause all feature-detection commands to fail.

Fixes #164

[lae]

Instead of adding the become parameters to each task, can you move the check tasks into their own block and use the become parameters on the block itself? (This does mean indenting all of the check tasks.)

(also just in case: please force push an amended commit to this branch rather than creating a new PR/new commit.)