Update README.md

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Author: keilw

README.md

@@ -2,6 +2,7 @@ unit-api
 ========
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 [![Build Status](https://drone.io/github.com/unitsofmeasurement/unit-api/status.png)](https://drone.io/github.com/unitsofmeasurement/unit-api/latest)
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 JSR 363 - Units of Measurement API