Moved middleware/ & schemas/ into api/.

api/schemas/Purchase.js

@@ -0,0 +1,20 @@
+const mongoose = require("mongoose");
+const Schema = mongoose.Schema;
+
+const Purchase = new Schema({
+  date: Date,
+  blue: Number,
+  red: Number,
+  yellow: Number,
+  green: Number,
+  bought: Number,
+  stolen: Number,
+  wines: [
+    {
+      type: Schema.Types.ObjectId,
+      ref: "Wine"
+    }
+  ]
+});
+
+module.exports = mongoose.model("Purchase", Purchase);