Remove message_count from metadata options

[fcevado]

closes #97

[coveralls]

Pull Request Test Coverage Report for Build f4e5c6c30a4da8f3a33e3674f5436b622b3e2f7a-PR-98

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 76.0%

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Totals
Change from base Build 610bd6fd6942fe56a69aea30cc9cbdaf8e544874:	0.0%
Covered Lines:	133
Relevant Lines:	175

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💛 - Coveralls

[josevalim]

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