Does Sword Burst target all creatures in range or only enemies? In 4th edition it only targeted enemies but I don't see any mention of enemies in the 5th edition version (Sword Coast Adventurer's Guide p.143).
It targets everyone in range
The spell's text reads:
Each creature within range, other than you
This is intended to be read literally, like most of 5e D&D, so it means that each creature within range (in this case, 5 feet of the caster) is affected by the spell.
The Sword Burst cantrip is from the Conjuration school, so unfortunately you can't get around this by using the Sculpt Spells feature from the Evocation wizard.
Affects all creatures in range
The spell language states (Sword Coast Adventurer's Guide pp143) :
Each creature within range[5'], other than you
Without differentiating between hostile/friendly/willing, the default is for every creature.