Clean up akkahttp-server/lagom tests

dd-java-agent/instrumentation/akka-http-10.0/src/lagomTest/groovy/LagomTest.groovy

@@ -2,7 +2,6 @@ import akka.NotUsed
 import akka.stream.javadsl.Source
 import akka.stream.testkit.javadsl.TestSink
 import net.bytebuddy.utility.JavaModule
-import org.junit.After
 
 import static java.util.concurrent.TimeUnit.SECONDS
 import datadog.trace.agent.test.AgentTestRunner
@@ -34,9 +33,8 @@ class LagomTest extends AgentTestRunner {
 
       // Looks like a compiler/packaging issue on akka's end. Or maybe this interface is dynamically generated.
       return false
-    } else {
-      return super.onInstrumentationError(typeName, classLoader, module, loaded, throwable)
     }
+    return super.onInstrumentationError(typeName, classLoader, module, loaded, throwable)
   }
 
   def setupSpec() {
@@ -94,6 +92,7 @@ class LagomTest extends AgentTestRunner {
         }
         span(1) {
           childOf span(0)
+          operationName 'EchoServiceImpl.tracedMethod'
         }
       }
     }

dd-java-agent/instrumentation/akka-http-10.0/src/test/groovy/AkkaHttpInstrumentationTest.groovy

@@ -103,7 +103,7 @@ class AkkaHttpInstrumentationTest extends AgentTestRunner {
             "error" true
             "error.type" RuntimeException.name
             "error.msg" errorMessage
-            "error.stack" tag("error.stack")
+            "error.stack" String
           }
         }
       }

dd-java-agent/instrumentation/play-2.4/src/latestDepTest/groovy/Play26Test.groovy

@@ -177,7 +177,7 @@ class Play26Test extends AgentTestRunner {
             "error" true
             "error.msg" "oh no"
             "error.type" RuntimeException.getName()
-            "error.stack" tag("error.stack")
+            "error.stack" String
           }
         }
       }

dd-java-agent/testing/src/main/groovy/datadog/trace/agent/test/TagsAssert.groovy

@@ -61,8 +61,4 @@ class TagsAssert {
   void assertTagsAllVerified() {
     assert tags.keySet() == assertedTags
   }
-
-  Object tag(String tagName) {
-    return tags[tagName]
-  }
 }