Fix code checks

dvc/utils/__init__.py

@@ -423,5 +423,5 @@ def resolve_output(inp, out):
 
 
 def is_exec_found(exec_name):
-    cmd = '({}) 2>/dev/null'.format(exec_name)
-    return hasattr(os, 'system') and os.system(cmd) == 0
+    cmd = "({}) 2>/dev/null".format(exec_name)
+    return hasattr(os, "system") and os.system(cmd) == 0

tests/func/test_utils.py

@@ -92,9 +92,9 @@ def test_makedirs_permissions(tmpdir):
 
 def test_is_exec_found_returns_true_when_program_exists():
     result = utils.is_exec_found("python")
-    assert result == True
+    assert result is True
 
 
 def test_is_exec_found_returns_false_when_program_is_missing():
     result = utils.is_exec_found("some-missing-program")
-    assert result == False
+    assert result is False