ENYO-4044: Update version to 2.5.0-pre.1

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>
Merge pull request #1345 from enyojs/ENYO-4044-aarontam

ENYO-4044: Update version to 2.5.0-pre.1