Tconnectsync

Fixes 38 which, due to changes on Tandem's side, prevented tconnectsync from connecting to Tandem's servers.

**Prior releases are likely to be broken by Tandem's changes, so please upgrade.**

**Breaking change:** The IOB synchronization feature was disabled by default, because it is not being utilized in the Nightscout UI at this time and is only available through the Nightscout API. It can be re-enabled with the `--features` flag.

**Full Changelog**: https://github.com/jwoglom/tconnectsync/compare/v0.6.4...v0.6.5

* autoupdate: reset API connection when event index change is recorded but no data is found, potential fix for 11
* secret: use TZ to infer TIMEZONE_NAME if set
* check: add additional output to --check-login

**Full Changelog**: https://github.com/jwoglom/tconnectsync/compare/v0.6.3...v0.6.4

**Full Changelog**: https://github.com/jwoglom/tconnectsync/compare/v0.6.2...v0.6.3

* When loading a .env file, explicitly looks for $HOME/.config/tconnectsync/.env if a .env file doesn't exist in the current directory.
* Allows environment variables to have higher precedence over .env file contents
* Fixes a bug relating to in-progress extended boluses.

**Full Changelog**: https://github.com/jwoglom/tconnectsync/compare/v0.6.0...v0.6.2

NEW: The following synchronization feature is disabled by default, but can be enabled via the --features flag:

`PUMP_EVENTS`: Events reported by the pump. Includes support for the following:
* Site/Cartridge Change (occurs for both a site change and a cartridge change)
* Empty Cartridge/Pump Shutdown (from my investigation, occurs either when the cartridge runs out of insulin OR you hard-shut off the pump)
* User Suspended (occurs when you manually disable insulin delivery)
* Exercise Mode (in Nightscout, appears with a start and end time)
* Sleep Mode (in Nightscout, appears with a start and end time)