fix: rm static from dockerfile (#62)

Author: jpfe-tid

Dockerfile

@@ -7,11 +7,11 @@ WORKDIR /src/prometheus-kafka-adapter
 ADD . /src/prometheus-kafka-adapter
 
 RUN go test
-RUN go build -tags static -o /prometheus-kafka-adapter
+RUN go build -o /prometheus-kafka-adapter
 
 FROM alpine:3.12
 
-RUN apk add --no-cache alpine-sdk 'librdkafka>=1.3.0'
+RUN apk add --no-cache 'librdkafka>=1.3.0'
 
 COPY --from=build /src/prometheus-kafka-adapter/schemas/metric.avsc /schemas/metric.avsc
 COPY --from=build /prometheus-kafka-adapter /