v1.8.1

Changed

• Clarity on the table to not use full name of day (Coburn Berry)
• Travis testing against erlang 19.1 and elixir 1.3.3 (Julius Beckmann)
• Don't allow "local" timezone. Replace Timex w. Calendar (Lau Taarnskov)

Fixed

• Global cannot be used directly (Po Chen)
• Support for timezones other than utc or local not in readme (Coburn Berry)
• Timezone as string not working in config (Daniel Roux)

Removed

• Timex references in readme (Coburn Berry)
• License badge in README