Fix TZ at Mount Everest

Some people care about the timezone at the summit of Mount Everest. Who knew?

fix #38

Merge pull request #39 from darkskyapp/ironwallaby/fix_38

fix #38

update to 2018i (mostly)

This release updates to 2018i. Since 2018i has overlapping timezone regions and this library's interface can't support that without a breaking change, we ignore the overlaps and institute our own biases for now.

We also completely revised the database generation software, so be advised that while this is a bugfix release, there may be lurking changes in the dataset.

fix #27

This fixes a few locations in Indiana.

Fix #25

v6.1.10

v6.1.10: fix #25

Fix #20 #24

v6.1.9

v6.1.9: fix #20 fix #24

Fix #23

v6.1.8

v6.1.8: fix #23

2018d

This release updates the backing data to 2018d.

Fix #18

v6.1.6

6.1.6: fix #18

Fix #14

Additionally, make the rebuild script a little more robust with shaky network connections.