some docstring improvements

jedi/api.py

@@ -39,17 +39,17 @@ class Script(object):
     |jedi|.
 
     :param source: The source code of the current file, separated by newlines.
-    :type source: string
+    :type source: str
     :param line: The line to perform actions on (starting with 1).
     :type line: int
     :param col: The column of the cursor (starting with 0).
     :type col: int
     :param source_path: The path of the file in the file system, or ``''`` if
         it hasn't been saved yet.
-    :type source_path: string or None
+    :type source_path: str or None
     :param source_encoding: The encoding of ``source``, if it is not a
         ``unicode`` object (default ``'utf-8'``).
-    :type source_encoding: string
+    :type source_encoding: str
     """
     def __init__(self, source, line, column, source_path,
                                  source_encoding='utf-8'):

jedi/parsing.py

@@ -326,7 +326,7 @@ class Class(Scope):
     Used to store the parsed contents of a python class.
 
     :param name: The Class name.
-    :type name: string
+    :type name: str
     :param supers: The super classes of a Class.
     :type supers: list
     :param start_pos: The start position (line, column) of the class.
@@ -359,7 +359,7 @@ class Function(Scope):
     Used to store the parsed contents of a python function.
 
     :param name: The Function name.
-    :type name: string
+    :type name: str
     :param params: The parameters (Statement) of a Function.
     :type params: list
     :param start_pos: The start position (line, column) the Function.