Don't explicitly read Astropy json sites file for timezone info

It's available as `EarthLocation.info.meta['timezone']`.
14 jobs for master in 10 minutes and 6 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Dist
passed #279115
dependencies/python3.6

00:00:30

passed #279116
dependencies/python3.7

00:00:30

passed #279110
sdist

00:00:28

passed #279113
macos_sierra
wheel/cp36-cp36m-macosx

00:00:28

passed #279111
wheel/cp36-cp36m-manylinux1

00:00:32

passed #279114
macos_sierra
wheel/cp37-cp37m-macosx

00:00:22

passed #279112
wheel/cp37-cp37m-manylinux1

00:00:32

 
  Test
passed #279117
docs

00:06:11

passed #279121
lint

00:00:22

passed #279120
test/coverage

00:09:05

82.79%
passed #279118
test/python3.6

00:09:09

passed #279119
test/python3.7

00:09:04

 
  Deploy
passed #279122
pages

00:00:23

passed pages:deploy

00:00:01