Add Gitter Badge

[kb1lqc]

Per #36 this is simply adding a badge linking to Gitter FaradayRF/Lobby

[coveralls]

Pull Request Test Coverage Report for Build 39

• 0 of 0 (NaN%) changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 69.88%

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Totals
Change from base Build 38:	0.0%
Covered Lines:	58
Relevant Lines:	83

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💛 - Coveralls