extraSpacing parameter in widget embed, fixes #355

[coveralls]

Pull Request Test Coverage Report for Build 616

• 2 of 8 (25.0%) changed or added relevant lines in 4 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.1%) to 36.355%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/index.js	0	1	0.0%
src/redux/actions.js	1	2	50.0%
src/redux/reducers.js	0	4	0.0%
<!--	Total:	2	8	25.0%	-->

Files with Coverage Reduction	New Missed Lines	%
src/redux/actions.js	1	15.75%
<!--	Total:	1		-->

Totals
Change from base Build 610:	0.1%
Covered Lines:	229
Relevant Lines:	668

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💛 - Coveralls