Use character range when x data is factor
Merge branch 'master' of github.com:ropensci/plotly into marianne-xrange-factors
Write test for hline over factor range
Prevent duplicate trace for hline over factor range
Merge branch 'master' of github.com:ropensci/plotly into marianne-xrange-factors
Support hline with facets
Merge pull request #139 from ropensci/marianne-xrange-factors

Support hline over a factor x range