csl: bump the sbt version across the board
csl: bump the sbt version across the board

Problem

We have mismatched sbt versions, but 1.2.8 seems to work better for 2.13.

Solution

Get consistent sbt versions across the board.

JIRA Issues: CSL-8768

Differential Revision: https://phabricator.twitter.biz/D363311

twitter/util,twitter/util,twitter/util