add test file to docker spin up

plugins/inputs/reader/dev/docker-compose.yml

@@ -0,0 +1,13 @@
+version: '3'
+
+services:
+  telegraf:
+      image: glinton/scratch
+      volumes:
+        - ./telegraf.conf:/telegraf.conf
+        - ../../../../telegraf:/telegraf
+        - ./json_a.log:/var/log/test.log
+      entrypoint:
+        - /telegraf
+        - --config
+        - /telegraf.conf

plugins/inputs/reader/dev/json_a.log

@@ -0,0 +1,14 @@
+{
+		"parent": {
+			"child": 3.0,
+			"ignored_child": "hi"
+		},
+		"ignored_null": null,
+		"integer": 4,
+		"list": [3, 4],
+		"ignored_parent": {
+			"another_ignored_null": null,
+			"ignored_string": "hello, world!"
+		},
+		"another_list": [4]
+	}