Change ctypes.c_int to ctypes.c_long since they're the same

weiji14 · weiji14 · commit 92029417db51 · 2020-05-21T14:45:42.000+12:00
According to https://docs.python.org/3/library/ctypes.html#ctypes-tutorial, `c_int` is just an alias for `c_long`.
diff --git a/pygmt/clib/conversion.py b/pygmt/clib/conversion.py
@@ -226,9 +226,9 @@ def kwargs_to_ctypes_array(argument, kwargs, dtype):
     --------
 
     >>> import ctypes as ct
-    >>> value = kwargs_to_ctypes_array('bla', {'bla': [10, 10]}, ct.c_int*2)
+    >>> value = kwargs_to_ctypes_array('bla', {'bla': [10, 10]}, ct.c_long*2)
     >>> type(value)
-    <class 'pygmt.clib.conversion.c_int_Array_2'>
+    <class 'pygmt.clib.conversion.c_long_Array_2'>
     >>> should_be_none = kwargs_to_ctypes_array(
     ...     'swallow', {'bla': 1, 'foo': [20, 30]}, ct.c_int*2)
     >>> print(should_be_none)
