Change MusicDirectory ids type to String.

Signed-off-by: Yahor Berdnikau <egorr.berd@gmail.com>

subsonic-api/src/integrationTest/kotlin/org/moire/ultrasonic/api/subsonic/SubsonicApiGetMusicDirectoryTest.kt

@@ -42,8 +42,8 @@ class SubsonicApiGetMusicDirectoryTest : SubsonicAPIClientTest() {
 
         response.body().musicDirectory `should not be` null
         with(response.body().musicDirectory) {
-            id `should equal to` 4836L
-            parent `should equal to` 300L
+            id `should equal to` "4836"
+            parent `should equal to` "300"
             name `should equal` "12 Stones"
             userRating `should equal to` 5
             averageRating `should equal to` 5.0f

subsonic-api/src/main/kotlin/org/moire/ultrasonic/api/subsonic/models/MusicDirectory.kt

@@ -3,8 +3,8 @@ package org.moire.ultrasonic.api.subsonic.models
 import com.fasterxml.jackson.annotation.JsonProperty
 import java.util.Calendar
 
-data class MusicDirectory(val id: Long = -1L,
-                          val parent: Long = -1L,
+data class MusicDirectory(val id: String = "",
+                          val parent: String = "",
                           val name: String = "",
                           val userRating: Int = 0,
                           val averageRating: Float = 0.0f,

ultrasonic/src/test/kotlin/org/moire/ultrasonic/data/APIMusicDirectoryConverterTest.kt

@@ -10,12 +10,12 @@ import org.moire.ultrasonic.api.subsonic.models.MusicDirectoryChild
 import java.util.Calendar
 
 /**
- * Unit test for extension functions in [APIMusicDirectoryConverter.kt] file.
+ * Unit test for extension functions in APIMusicDirectoryConverter.kt file.
  */
 class APIMusicDirectoryConverterTest {
     @Test
     fun `Should convert MusicDirectory entity`() {
-        val entity = MusicDirectory(id = 1982L, parent = 345L, name = "some-name", userRating = 3,
+        val entity = MusicDirectory(id = "1982", parent = "345", name = "some-name", userRating = 3,
                 averageRating = 3.4f, starred = Calendar.getInstance(), playCount = 10,
                 childList = listOf(MusicDirectoryChild(1L), MusicDirectoryChild(2L)))