refactor: move indexable test files to separate folder

test/resources/indexable/Periodical.1.json

@@ -0,0 +1,35 @@
+{
+  "errorNames": [],
+  "instance": {
+    "type": "periodical",
+    "uid": "d921479e-4d35-5cd1-b64a-939cbe40a5b0",
+    "name": "London magazine : a review of literature and the arts",
+    "categories": [
+      "journal"
+    ],
+    "firstPublished": "1954",
+    "publications": [
+      {
+        "uid": "603a6574-8910-588a-9e83-cd26e6988c74",
+        "type": "publication event",
+        "locations": [
+          "London"
+        ],
+        "publisher": "London Magazine",
+        "name": "London Magazine"
+      }
+    ],
+    "ISSNs": [
+      "0024-6085"
+    ],
+    "sameAs": "https://hds2test.hebis.de/ubffm/Record/HEB046847146",
+    "origin": {
+      "indexed": "2018-09-11T12:30:00Z",
+      "name": "HeBIS HDS",
+      "originalId": "HEB046847146",
+      "type": "remote",
+      "url": "https://hds2test.hebis.de/ubffm/"
+    }
+  },
+  "schema": "SCPeriodical"
+}