TimeRange is not visible

TimeRange was without modifiers, leading to "The type TimeRange is not visible"
errors
Merge pull request #1 from caarlos0/feature/fix-timerange-visibility

TimeRange is not visible
Added getElapsedWeeks

also made some tests a little more deterministic.

PS: weeks are rounded UP
Merge pull request #2 from caarlos0/feature/elapsed-weeks

Added getElapsedWeeks