Auto-format all files using yapf and pre-commit (#1173)

Automatic fixes produced by yapf formatting using `--style=google`, as
well as common pre-commit checks such as trailing whitespace removal,
double quote fixer, and newlines at the end of a file.

src/tools/a_atleast_b.py

@@ -9,7 +9,7 @@ b = sys.argv[2]
 #result = version.parse(a) >= version.parse(b)
 result = LooseVersion(a) >= LooseVersion(b)
 if result:
-  print('OK: %s is equal or newer than %s' % (a, b))
+    print('OK: %s is equal or newer than %s' % (a, b))
 else:
-  print('ERROR: %s is older than %s' % (a, b))
+    print('ERROR: %s is older than %s' % (a, b))
 sys.exit(not result)