slicedelete tests
enumerable  slicedelete cases
more slicedelete tests; correct slicedelete error formatting
LazyAssert - exception messages are formatted on demand
enumerable slicedelete +++ case has been implemented
enumerable slicedelete ++- case has been implemented
enumerable slicedelete --+ case has been implemented
enumerable slicedelete --- case has been implemented
enumerable slicedelete +-+ case has been implemented
enumerable slicedelete +-- step=-1 case has been implemented
enumerable slicedelete +-- step < -1 case have been implemented
enumerable slicedelete +-- case - code has been shortened
enumerable slicedelete -+- case has been implemented
enumerable slicedelete -++ && to == null case has been implemented
enumerable slicedelete -++ && to != null && step == 1 case has been implemented
enumerable slicedelete -++ && to != null && step != 1 case has been implemented
Merge branch 'feature/slicedelete_for_enumerables' into develop
tests have been optimized