Make message more clear if file is not found in create_image_from_file view and added gunicorn

Pipfile

@@ -12,6 +12,7 @@ requests = "*"
 flask = "*"
 flask-restful = "*"
 etcd3 = "*"
+gunicorn = "*"
 
 [requires]
 python_version = "3.7"

Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "8793670eeaec12ab75f38686e67ba0c4f7d27a7b6da26d9c692b55621c865f63"
+            "sha256": "87f5447c7fa8d96dacc7c638075cc31842ef676f6d1c35214e1960572d44e929"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -104,6 +104,14 @@
             ],
             "version": "==1.21.1"
         },
+        "gunicorn": {
+            "hashes": [
+                "sha256:aa8e0b40b4157b36a5df5e599f45c9c76d6af43845ba3b3b0efe2c70473c2471",
+                "sha256:fa2662097c66f920f53f70621c6c58ca4a3c4d3434205e608e121b5b3b71f4f3"
+            ],
+            "index": "pypi",
+            "version": "==19.9.0"
+        },
         "idna": {
             "hashes": [
                 "sha256:c357b3f628cf53ae2c4c05627ecc484553142ca23264e593d327bcde5e9c3407",

main.py

@@ -101,7 +101,9 @@ class CreateImage(Resource):
 
         file_entry = client.get(f"/v1/files/{image_file_uuid}")
         if file_entry is None:
-            return {"Message": "Image File Not Found"}, 400
+            return {
+                "Message":
+                f"Image File with uuid '{image_file_uuid}' Not Found"}, 400
 
         file_entry_value = json.loads(file_entry.value)