Amend test.py for os dependendent directory separator char

It was failing on Windows

Author: AndreaLanfranchi

tests/test_find.py

@@ -1,3 +1,4 @@
+import os
 import cv2
 import pandas as pd
 from deepface import DeepFace
@@ -10,7 +11,7 @@
 
 
 def test_find_with_exact_path():
-    img_path = "dataset/img1.jpg"
+    img_path = os.path.join("dataset","img1.jpg")
     dfs = DeepFace.find(img_path=img_path, db_path="dataset", silent=True)
     assert len(dfs) > 0
     for df in dfs:
@@ -30,7 +31,7 @@ def test_find_with_exact_path():
 
 
 def test_find_with_array_input():
-    img_path = "dataset/img1.jpg"
+    img_path = os.path.join("dataset","img1.jpg")
     img1 = cv2.imread(img_path)
     dfs = DeepFace.find(img1, db_path="dataset", silent=True)
     assert len(dfs) > 0
@@ -52,7 +53,7 @@ def test_find_with_array_input():
 
 
 def test_find_with_extracted_faces():
-    img_path = "dataset/img1.jpg"
+    img_path = os.path.join("dataset","img1.jpg")
     face_objs = DeepFace.extract_faces(img_path)
     img = face_objs[0]["face"]
     dfs = DeepFace.find(img, db_path="dataset", detector_backend="skip", silent=True)