Support only lower or upper bound for axis range

[iynehz]

The Python implementation supports it https://plotly.com/python/axes/#setting-only-a-lower-or-upper-bound-for-range . I think it's basically about setting something like [4.5, null] to range at javascript level.

[andrei-ng]

Support was added in #314
@iynehz , please let me know if it works for your use case(s)