Bumped Vega to 2.5.2->2.6.0, datalib 1.6.3->1.7.1
Bumped Vega to 2.5.2->2.6.0, datalib 1.6.3->1.7.1

Change-Id: I550870806bd93a2773452e6a3fd109f96549778e

wikimedia/mediawiki-extensions-Graph,wikimedia/mediawiki-extensions-Graph