Fix Docker image building by upgrading to Go 1.17 (G-Research#96)

* Run `go tidy` and upgrade to Go 1.17

* Fix grpc-health-probe installation warning

Dockerfile

@@ -4,7 +4,7 @@ ADD . /src
 WORKDIR /src
 RUN apk add git
 ARG GRPC_HEALTH_PROBE_VERSION=v0.3.0
-RUN go get github.com/grpc-ecosystem/grpc-health-probe@${GRPC_HEALTH_PROBE_VERSION}
+RUN go install github.com/grpc-ecosystem/grpc-health-probe@${GRPC_HEALTH_PROBE_VERSION}
 
 ARG GERAS_VERSION="development"
 ARG BUILD_USER="docker"

go.mod

@@ -1,21 +1,22 @@
 module github.com/G-Research/geras
 
-go 1.15
+go 1.17
 
 require (
 	github.com/G-Research/opentsdb-goclient v0.0.0-20191219203319-f9f2aa5b2624
 	github.com/go-kit/kit v0.9.0
+	github.com/grpc-ecosystem/go-grpc-middleware v1.0.0
 	github.com/grpc-ecosystem/go-grpc-prometheus v0.0.0-20181025070259-68e3a13e4117
 	github.com/pkg/errors v0.8.1
 	github.com/prometheus/client_golang v1.1.0
 	github.com/prometheus/common v0.6.0
 	github.com/prometheus/prometheus v1.8.2-0.20190913102521-8ab628b35467 // v1.8.2 is misleading as Prometheus does not have v2 module.
 	github.com/thanos-io/thanos v0.7.0
-	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.16.0 // indirect
-	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.16.0 // indirect
-	go.opentelemetry.io/contrib/propagators v0.16.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.16.0
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.16.0
+	go.opentelemetry.io/contrib/propagators v0.16.0
 	go.opentelemetry.io/otel v0.16.0
-	go.opentelemetry.io/otel/exporters/trace/jaeger v0.16.0 // indirect
+	go.opentelemetry.io/otel/exporters/trace/jaeger v0.16.0
 	golang.org/x/net v0.0.0-20201031054903-ff519b6c9102
 	google.golang.org/grpc v1.34.0
 )