bump plotly version and edition to 2021 #368

Job	Run time
Clippy	1m 41s
Build Examples (3d_charts)	32s
Code Coverage	1m 54s
Build Wasm Examples (wasm-yew-minimal)	51s
Build Examples (basic_charts)	27s
Build Examples (custom_controls)	22s
Rustfmt	13s
semver	3m 27s
Build Examples (financial_charts)	29s
Tests (ubuntu-latest)	2m 15s
Build Examples (images)	39s
Tests (windows-latest)	3m 55s
Tests (macos-latest)	32m 1s
Build Examples (kaleido)	1m 36s
Build Examples (maps)	25s
Build Examples (ndarray)	32s
Build Examples (scientific_charts)	22s
Build Examples (shapes)	29s
Build Examples (subplots)	21s
	52m 31s

Provide feedback