Update Modulefile for 1.0.0 release

Update Modulefile for 1.0.0 release

This commit increments the version number to 1.0.0 for a new
Puppet Forge release.

Version 1.0.0 is a backwards incompatible release of puppetlabs-apt.

The major change is to the apt::backports class which had its repos
property modified on Ubuntu systems to include the main repository
in addition to universe, multiverse & restricted.

Additionally, the following bug fixes or minor enhancements were
introduced:
* Cleanup of style, variable scope and bug fixes.
* Exec resources now set the `logoutput` parameter to on_failure.
* Adds a timeout parameter to the apt::force defined resource type
* Allow pinning on version numbers in apt::pin
* Allow optional order parameter to apt::pin
* Allow ability to fill in pin explanation

Contributions were provided by the following fine folk:
Nan Liu
Anton Lindström
ytjohn
Steffen Zieger
Erik Dalén
Jonathan Araña Cruz
sathlan
Branan Purvine-Riley
Alexander Menk