Fix validator tests

Author: jonmmease

packages/python/plotly/_plotly_utils/tests/validators/test_basetraces_validator.py

@@ -84,7 +84,7 @@ def test_rejection_type(validator):
     with pytest.raises(ValueError) as validation_failure:
         validator.validate_coerce(val)
 
-    assert "Invalid value" in str(validation_failure.value)
+    assert "Invalid element(s)" in str(validation_failure.value)
 
 
 def test_rejection_element_type(validator):

packages/python/plotly/_plotly_utils/tests/validators/test_imageuri_validator.py

@@ -1,8 +1,8 @@
 import base64
-
+import os
 import pytest
 from _plotly_utils.basevalidators import ImageUriValidator
-import numpy as np
+
 from PIL import Image
 
 
@@ -28,7 +28,9 @@ def test_validator_acceptance(val, validator):
 def test_validator_coercion_PIL(validator):
     # Single pixel black png (http://png-pixel.com/)
 
-    img_path = '_plotly_utils/tests/resources/1x1-black.png'
+    tests_dir = os.path.dirname(os.path.dirname(__file__))
+    img_path = os.path.join(tests_dir, 'resources', '1x1-black.png')
+
     with open(img_path, 'rb') as f:
         hex_bytes = base64.b64encode(f.read()).decode('ascii')
         expected_uri = 'data:image/png;base64,' + hex_bytes