Clarify test intention

Author: felipecrs

tests/integration/api_build_test.py

@@ -202,25 +202,25 @@ def test_build_isolation(self):
             pass
 
     @requires_api_version('1.38')
-    def test_build_with_buildkit(self):
+    def test_build_buildkit_heredoc(self):
         script = io.BytesIO('\n'.join([
             'FROM scratch',
             'COPY <<EOF greeting.txt',
             'hello world',
             'EOF'
         ]).encode('ascii'))
 
-        self.tmp_imgs.append('buildkit')
+        self.tmp_imgs.append('buildkit-heredoc')
 
         stream = self.client.build(
-            fileobj=script, tag='buildkit',
+            fileobj=script, tag='buildkit-heredoc',
             version='2'
         )
 
         for _chunk in stream:
             pass
 
-        assert self.client.inspect_image('buildkit')
+        assert self.client.inspect_image('buildkit-heredoc')
 
     @requires_api_version('1.23')
     def test_build_labels(self):