prometheus-nginx-exporter: 0.4.1 -> 0.4.2, run tests

pkgs/servers/monitoring/prometheus/nginx-exporter.nix

@@ -2,7 +2,7 @@
 
 buildGoPackage rec {
   name = "nginx_exporter-${version}";
-  version = "0.4.1";
+  version = "0.4.2";
 
   goPackagePath = "github.com/nginxinc/nginx-prometheus-exporter";
 
@@ -14,9 +14,11 @@ buildGoPackage rec {
     rev = "v${version}";
     owner = "nginxinc";
     repo = "nginx-prometheus-exporter";
-    sha256 = "0c5bxl9xrd4gh2w5wyrzghmbcy9k1khydzml5cm0rsyqhwsvs8m5";
+    sha256 = "023nl83w0fic7sj0yxxgj7jchyafqnmv6dq35amzz37ikx92mdcj";
   };
 
+  doCheck = true;
+
   meta = with stdenv.lib; {
     description = "NGINX Prometheus Exporter for NGINX and NGINX Plus";
     homepage = "https://github.com/nginxinc/nginx-prometheus-exporter";