add build badge to Readme

Signed-off-by: Nick Revin <n@nrvn.cc>

README.md

@@ -1,5 +1,6 @@
 # Redis Operator
 
+[![Build Status](https://cloud.drone.io/api/badges/amaizfinance/redis-operator/status.svg)](https://cloud.drone.io/amaizfinance/redis-operator)
 [![Go Report Card](https://goreportcard.com/badge/github.com/amaizfinance/redis-operator)](https://goreportcard.com/report/github.com/amaizfinance/redis-operator)
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@@ -12,7 +13,7 @@ The basic features have been completed, and while no breaking API changes are cu
 
 ## Overview
 
-Redis Operator can be considered a Kubernetes-native replacement for [Redis Sentinel][sentinel]. It creates the [Redis][Redis] instances and maintains high availability and automatic failover.
+Redis Operator can be considered a Kubernetes-native replacement for [Redis Sentinel][sentinel]. It creates the [Redis] instances and maintains high availability and automatic failover.
 
 Fundamental things to know about Redis Operator: