v0.1.5: Release 0.1.5

 * Add. Allow use `ltn12.source` as file argument
 * Add. Allows use cURL to send email

v0.1.4: Release 0.1.4

 * Add. `create` function can create SSL/TLS connection.
 * Fix. Correct encodes name of attachments.
 * Fix. Create global variable.

v0.1.3: Release 0.1.3

* Add supports SMTPS using LuaSec

v0.1.2: Release 0.1.2

Add. `server` option supports port number and custom socket ctor
Fix. Set correct title in `To` header
Fix. Detect incorrect decoder name