Add Airing Progression Model (#24)

data/src/main/java/co/anitrend/data/model/response/core/airing/AiringProgression.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2019  AniTrend
+ *
+ *     This program is free software: you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License as published by
+ *     the Free Software Foundation, either version 3 of the License, or
+ *     (at your option) any later version.
+ *
+ *     This program is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ *     You should have received a copy of the GNU General Public License
+ *     along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package co.anitrend.data.model.response.core.airing
+
+/** [AiringProgression](https://anilist.github.io/ApiV2-GraphQL-Docs/airingprogression.doc.html)
+ * Score & Watcher stats for airing anime by episode and mid-week
+ *
+ * @param episode The episode the stats were recorded at. .5 is the mid point between 2 episodes airing dates
+ * @param score The average score for the media
+ * @param watching The amount of users watching the anime
+ */
+data class AiringProgression(
+    val episode: Float?,
+    val score: Float?,
+    val watching: Int?
+)