Should EIP module be using timezones for tagging resources?

[ina-stoyanova]

Context: Currently eip.go tags resources with a timestamp ignorant of TimeZones: 2006-01-02 15:04:05.

The ecs_cluster module already has that in place & uses UTC & RFC3339 as a standard for timestamp tagging.

Suggestion: - update the eip module with TimeZone awareness

• refactor/extract out the commonalities between ecs_cluster & eip code for tagging a resource when it's first seen & retrieving the tag