Update constants file directly with new module to installer version map

[GuySartorelli]

#20 adds a script which can be run to get the versions for modules being released for a given version of installer.
This currently just outputs to the console, and the developer must manually copy the contents into the constant, including adding a new key, which may lead to human error at some stage.

Update the script so that it automatically adds the output to the correct key of the constant directly in the constants file, including merging any values that may already be against that version of installer, and creating the key into the array if it's not already there.