make tests optional (for jitpack)

Author: adamint

src/commonTest/kotlin/com.adamratzman/spotify/Common.kt

@@ -15,7 +15,7 @@ val api = when {
             }
         }.build()
     }
-    else -> {
+    _clientId != null -> {
         spotifyClientApi {
             credentials {
                 clientId = _clientId
@@ -27,6 +27,7 @@ val api = when {
             }
         }.build()
     }
+    else -> null
 }
 
 expect fun getEnvironmentVariable(name: String): String?

src/commonTest/kotlin/com.adamratzman/spotify/pub/BrowseApiTest.kt

@@ -17,7 +17,7 @@ import org.spekframework.spek2.style.specification.describe
 
 class BrowseApiTest : Spek({
     describe("Browse test") {
-        val b = api.browse
+        val b = api?.browse ?: return@describe
         it("get genre seeds") {
             assertTrue(b.getAvailableGenreSeeds().complete().isNotEmpty())
         }

src/commonTest/kotlin/com.adamratzman/spotify/pub/PublicAlbumsApiTest.kt

@@ -15,7 +15,7 @@ import org.spekframework.spek2.style.specification.describe
 
 class PublicAlbumsApiTest : Spek({
     describe("Public Albums test") {
-        val a = api.albums
+        val a = api?.albums ?: return@describe
         describe("get albums") {
             it("singular album") {
                 assertNull(a.getAlbum("asdf", Market.FR).complete())

src/commonTest/kotlin/com.adamratzman/spotify/pub/PublicArtistsApiTest.kt

@@ -15,7 +15,7 @@ import org.spekframework.spek2.style.specification.describe
 
 class PublicArtistsApiTest : Spek({
     describe("Public Artists test") {
-        val a = api.artists
+        val a = api?.artists?: return@describe
         describe("get artists") {
             it("invalid artist") {
                 assertNull(a.getArtist("adkjlasdf").complete())

src/commonTest/kotlin/com.adamratzman/spotify/pub/PublicFollowingApiTest.kt

@@ -10,7 +10,7 @@ import org.spekframework.spek2.style.specification.describe
 
 class PublicFollowingApiTest : Spek({
     describe("Public Following test") {
-        val f = api.following
+        val f = api?.following?: return@describe
         describe("do users follow playlist") {
             it("invalid users, valid playlist") {
                 assertFailsWith<SpotifyException.BadRequestException> { f.areFollowingPlaylist("37i9dQZF1DXcBWIGoYBM5M", "udontexist89").complete()[0] }

src/commonTest/kotlin/com.adamratzman/spotify/pub/PublicPlaylistsApiTest.kt

@@ -14,7 +14,7 @@ import org.spekframework.spek2.style.specification.describe
 
 class PublicPlaylistsApiTest : Spek({
     describe("Public playlists test") {
-        val p = api.playlists
+        val p = api?.playlists?: return@describe
         describe("get user's playlists") {
             it("available user should return playlists") {
                 assertTrue(p.getUserPlaylists("adamratzman1").complete().items.isNotEmpty())

src/commonTest/kotlin/com.adamratzman/spotify/pub/PublicTracksApiTest.kt

@@ -13,7 +13,7 @@ import org.spekframework.spek2.style.specification.describe
 
 class PublicTracksApiTest : Spek({
     describe("Track API (Public View) test") {
-        val t = api.tracks
+        val t = api?.tracks?: return@describe
         describe("get track") {
             it("known track should return author name") {
                 assertEquals("Bénabar", t.getTrack("5OT3k9lPxI2jkaryRK3Aop").complete()!!.artists[0].name)

src/commonTest/kotlin/com.adamratzman/spotify/pub/PublicUserApiTest.kt

@@ -10,6 +10,7 @@ import org.spekframework.spek2.style.specification.describe
 
 class PublicUserApiTest : Spek({
     describe("Public User test") {
+        api?.users ?: return@describe
         describe("get user") {
             it("available user should return author name") {
                 assertTrue { catch { api.users.getProfile("adamratzman1").complete()!!.followers.total } != null }

src/commonTest/kotlin/com.adamratzman/spotify/pub/SearchApiTest.kt

@@ -13,7 +13,7 @@ import org.spekframework.spek2.style.specification.describe
 
 class SearchApiTest : Spek({
     describe("Search API test") {
-        val s = api.search
+        val s = api?.search ?: return@describe
         describe("search multiple") {
             it("valid request") {
                 val query = s.search("lo", *SearchApi.SearchType.values()).complete()

src/commonTest/kotlin/com.adamratzman/spotify/utilities/JsonTests.kt

@@ -22,6 +22,8 @@ import org.spekframework.spek2.style.specification.describe
 @UnstableDefault
 class JsonTests : Spek({
     describe("json serialization tests") {
+        api?.artists ?: return@describe
+
         it("artist serialization") {
             assertTrue(
                 Json.stringify(