`in` on an empty range should be false, not an error

Previously:

```julia> 1 in 1:0
ERROR: min: range is empty
 in minimum at range.jl:100
 in in at range.jl:417```

All other collections (including float ranges) simply return false on an empty collection.  This (very very simple) PR fixes this and adds a few basic test cases in `test/ranges.jl`.