Help text error for migrate:latest

Changed the help text for migrate:latest as described in the documentation.
Merge pull request #342 from NathanRSmith/patch-1

Help text error for migrate:latest
support password, ssl, stream options in node-mysql2 - #341
Fix #282, add raw support in groupBy / orderBy

Adds groupByRaw, orderByRaw as convenience methods
for groupBy(raw) / orderBy(raw)
release 0.6.19