Add data files for missing time zones from issue #16
Merge pull request #17 from enthuseinc/feature/issue_16

Add data files for missing time zones from issue #16
Add basic structure for TZ Rule object.

Eventually this object will parse lines like this

    Rule	Zion	1940	only	-	Jun	 1	0:00	1:00	D

into a `Timezone::Rule` object that can be applied to a collection of
zone entries.
Bumped to version 0.2.1.
Fix test for Travis.
Try another fix for Travis.
Updated changelog.
Add rule parsing.
Simplify timezone.rb
Add Entry object and tzdata entry parsing.
Updated CONTRIBUTING guide with new TZDATA website.
Added comments to new Entry and Rule files.