added test TeamMember.shouldHaveEmptyExpositionWhenCreated
added "use strict" in model classes
removed dummy test
added test TeamMember.shouldHaveGivenNameWhenCreated
added test TeamMemberController.shouldChangeEstimateToGivenWhenProvided
added test TeamMember.shouldRemoveEstimateWhenRecalled
removed "use strict" from test
TeamMemberController.shouldThrowWhenEmptyCardProvided
added test TeamMemberController.shouldThrowWhenEstimateIsAlreadyProvided