Our code had an unspoken assumption that only one apiClient is created
during the course of a command. Violating this assumption is fine in
almost all cases, but not when we need to do a re-auth to add a new
oauth scope to a user's token.
There is likely a more elegant solution to the problem but until then
this changes determineBaseRepo to use an existing apiClient.
this commit add very basic non-interactive PR reviewing. You can either
review the "current" or a passed PR (number or URL) as approved, changes
requested, or commented via CLI flags.
