Revert "Upgrade to Specs2 2.x."  Not as compatible as I'd hoped.
Defer to 2.3.x.

This reverts commit 847414f76dcd04a08e76fae56d05e646a144219a.
Merge branch '2.2.x_2.9' into 2.2.x_2.10
Merge branch '2.2.x_2.9' into 2.3.x_2.9
Merge branch '2.3.x_2.9' into 2.3.x_2.10
Merge branch '2.2.x_2.10' into 2.3.x_2.10