v0.18.4

PlotlyJS v0.18.4

Diff since v0.18.3

Closed issues:

• No plot is displayed with version 0.16.4 (#392)
• plotly.js version is stuck at 1.58.5 rather than 2.2.1 (#394)
• Sub plotting broken (#403)
• Title not centered (#405)
• Conflict with Makie plot system, improvement suggested (#406)
• Too many entries in subplots legends (#407)
• Style() not defined (#408)
• no method get(::String, ...) for PlotlyJS on dataframe (#409)

Merged pull requests:

• fix subplot docs (#404) (@sglyon)
• Fix add trace (#410) (@sglyon)