Return uniform 200 response for new and existing API key registrations

src/main/scala/dpla/api/Routes.scala

@@ -410,9 +410,9 @@ class Routes(
       case SmrArchiveSuccess =>
         complete(smrArchiveSuccessMessage)
       case NewApiKey(email) =>
-        complete(newKeyMessage(email))
+        complete(apiKeyMessage(email))
       case ExistingApiKey(email) =>
-        complete(existingKeyResponse(email))
+        complete(apiKeyMessage(email))
       case DisabledApiKey(email) =>
         complete(disabledKeyResponse(email))
       case NotFoundFailure =>
@@ -506,16 +506,6 @@ class Routes(
       entity = errorEntity("bad_request", message)
     )
 
-  private def existingKeyResponse(email: String): HttpResponse =
-    HttpResponse(
-      Conflict,
-      entity = errorEntity(
-        "existing_key",
-        s"There is already an API key for $email" +
-          ". We have sent a reminder message to that address."
-      )
-    )
-
   private def disabledKeyResponse(email: String): HttpResponse =
     HttpResponse(
       Conflict,
@@ -527,8 +517,8 @@ class Routes(
       )
     )
 
-  private def newKeyMessage(email: String): String =
-    s"API key created and sent to $email."
+  private def apiKeyMessage(email: String): String =
+    s"Your API key has been sent to $email."
 
   private val smrArchiveSuccessMessage: String =
     s"Your request has been received."

src/test/scala/dpla/api/v2/authentication/MockPostgresClientExistingKey.scala

@@ -22,8 +22,8 @@ object MockPostgresClientExistingKey {
       case ValidApiKey(_, _) =>
         Behaviors.unhandled
 
-      case ValidEmail(_, replyTo) =>
-        replyTo ! AccountFound(account)
+      case ValidEmail(email, replyTo) =>
+        replyTo ! AccountFound(account.copy(email = email))
         Behaviors.same
 
       case _ =>

src/test/scala/dpla/api/v2/endToEnd/PostgresErrorTest.scala

@@ -44,16 +44,16 @@ class PostgresErrorTest extends AnyWordSpec with Matchers
   }
 
   "/api_key/[email] route" should {
-    "return Conflict if email has existing api key" in {
+    "return OK if email has existing api key" in {
       lazy val routes: Route =
         new Routes(itemRegistry, pssRegistry,
           apiKeyRegistryExistingKey, smrRegistry).applicationRoutes
 
       val request = Post("/v2/api_key/email@example.com")
 
       request ~> Route.seal(routes) ~> check {
-        status shouldEqual StatusCodes.Conflict
-        contentType should === (ContentTypes.`application/json`)
+        status shouldEqual StatusCodes.OK
+        entityAs[String] shouldEqual "Your API key has been sent to email@example.com."
       }
     }
   }