target.py docstring does not reflect all possible values for objective param

[matSciMalcolm]

The Target object may now accept a specific value in addition to "Min" or "Max", but this is not expressed within the existing docstring.

If the following could be added to the target.py docstring (either "Max" or "Min") ->(either "Max", "Min", or a specific value for the property) I think it would help users better debug/build tools.

 """
 The optimization target for a design run. Consists of
 the name of the output column to optimize and the objective
 (either "Max", "Min", or a specific value for the property)
 """

 def __init__(self, name, objective):
 """
 Constructor.

 :param name: The name of the target output column
 :type name: str
 :param objective: The optimization objective; either "Min",
 "Max", or a specific value for the property
 :type objective: str
 """