Add rule for modifying enviroment variables.

[stefanbirkner]

@victornoel could you please check whether this rule fulfills your needs. Unlike your code this rule does not have a constructor that accepts a map of variables. Please tell me if you need this feature. I didn't implement it now because it adds complexity to the rule.

[victornoel]

It's great. Combined with a @Before method it would do the same, right?

Thank you :)

[victornoel]

But there is something that seems strange to me, not sure thought, originalVariables is a reference to the original environment map, not a copy, so when set() is called, isn't the object referenced by originalVariables the map that is modified?

[stefanbirkner]

You're right. Thanks for investigating the code.

[stefanbirkner]

Merged: e778307cdcd423030a42502342b0cfcc79048655