Even more URL redirects

CRAN submission

bump to release version; submit to CRAN

bump version in NEWS

CRAN version v4.8.0

Also, clean up examples on help(add_trace)

bump version in NEWS

Merge pull request plotly#728 from nielsenmarkus11/nielsenmarkus11-pa…

…tch-1

Add `source` argument to both the source plot and `event_data` function

Merge pull request plotly#586 from ropensci/update/plotlyjs-1.11.0

update to plotly 1.11.0

documentation changes for R CMD check

Merge pull request plotly#574 from ropensci/fix/axis-labels

use Plotly axis titles if not facetted