update dropwizard version and add a super simple test

ktor-features/ktor-metrics/build.gradle

@@ -3,8 +3,8 @@ kotlin {
     sourceSets {
         jvmMain {
             dependencies {
-                api group: 'io.dropwizard.metrics', name: 'metrics-core', version: '3.2.4'
-                api group: 'io.dropwizard.metrics', name: 'metrics-jvm', version: '3.2.4'
+                api group: 'io.dropwizard.metrics', name: 'metrics-core', version: '4.1.0'
+                api group: 'io.dropwizard.metrics', name: 'metrics-jvm', version: '4.1.0'
             }
         }
     }

ktor-features/ktor-metrics/jvm/test/io/ktor/metrics/dropwizard/DropwizardMetricsTests.kt

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2014-2019 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package io.ktor.metrics.dropwizard
+
+import com.codahale.metrics.*
+import io.ktor.application.*
+import io.ktor.response.*
+import io.ktor.routing.*
+import io.ktor.server.testing.*
+import org.junit.*
+import org.junit.Assert.*
+
+
+class DropwizardMetricsTests {
+
+    @Test
+    fun `meter is registered for a given path`(): Unit = withTestApplication {
+        val testRegistry = MetricRegistry()
+
+        application.install(DropwizardMetrics) {
+            registry = testRegistry
+        }
+
+        application.routing {
+            get("/uri") {
+                call.respond("hello")
+            }
+        }
+
+        handleRequest {
+            uri = "/uri"
+        }
+
+        assertEquals(1, testRegistry.meter("/uri/(method:GET).200").count)
+    }
+}