Summary: This should help reduce test flakiness.
Reviewed By: xavierd
Differential Revision: D19872952
fbshipit-source-id: d66f6c404534b3f47903b478e3cdfdda5ed46284
Summary:
In preparation for merging fb-mercurial sources to the Eden repository,
move everything from the top-level directory into an `eden/scm`
subdirectory.