Require minor version in Deprecation Notifier

[ChefAustin]

PR to fix #67

• Added array elements (expectedVersionArray[2] and systemVersionArray[2]) which are responsible for running OS minor version check-logic.
• Adds functionality to allow for minor versions in expectedVersion.
• Amended comment reflecting above change requirements.

Tested on macOS 10.13.2 using 10.13.0, 10.13.1, 10.13.2, 10.13.3 as expectedVersion; all passed.

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[russellhancox]

Hi Austin,

This change would fail to show properly on machines running 10.13, as the SystemVersion.plist contains just "10.13". Could you change it to handle the case where systemVersionArray and/or expectedVersionArray only have 2 elements?

E.g. all of these states?

expectedVersion	systemVersion	state
10.12.6	10.12.5	display
10.13	10.12.6	display
10.13	10.13	quit
10.13	10.13.2	quit
10.13.2	10.13	display
10.13.2	10.13.1	display
10.13.2	10.13.2	quit

[ChefAustin]

Valid points. @russellhancox. I'll poke at it a bit more. Thanks.

[googlebot]

CLAs look good, thanks!

[googlebot]

CLAs look good, thanks!

[russellhancox]

Thanks for the contribution!