Fixed remove duplicate (TheAlgorithms#2470)

* fixed remove duplicate

* fixup! Format Python code with psf/black push

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

strings/remove_duplicate.py

@@ -1,14 +1,15 @@
-""" Created by sarathkaul on 14/11/19 """
-
-
 def remove_duplicates(sentence: str) -> str:
     """
-    Reomove duplicates from sentence
+    Remove duplicates from sentence
     >>> remove_duplicates("Python is great and Java is also great")
     'Java Python also and great is'
+    >>> remove_duplicates("Python   is      great and Java is also great")
+    'Java Python also and great is'
     """
-    return " ".join(sorted(set(sentence.split(" "))))
+    return " ".join(sorted(set(sentence.split())))
 
 
 if __name__ == "__main__":
-    print(remove_duplicates("INPUT_SENTENCE"))
+    import doctest
+
+    doctest.testmod()