Co-authored-by: Hanen Alrwasheda <NiToThePowerOf2Plus2@users.noreply.github.com>
Co-authored-by: elkazelka <elkazelka@users.noreply.github.com>
Co-authored-by: mzeoba <mysuradze@gmail.com>

Database in Sequelize implemented

Closes #15

See merge request swp-ws21-fahrtenbuch/team-einhorn/fahrtenbuch!7

Implement Mail Sending & Template

- added sending mails via nodemailer  -> .env may need to be updated
- added template loading from server/src/assets
	* special email html for readability across multiple mail clients
	* expressions inside {{}} are replaced by the values of the replace argument in the sendMail function
	* templates are both in txt and html for mail clients that don't support html

Closes #18

See merge request swp-ws21-fahrtenbuch/team-einhorn/fahrtenbuch!10

some salt according to: https://git.imp.fu-berlin.de/swp-ws21-fahrtenbuch/team-einhorn/fahrtenbuch/-/merge_requests/7#note_79858

Fix for `Parameter 'res' implicitly has an 'any' type.` using QueryResult.  Quick (temporary) Fix for missing "pg"-module.

- removed process env check (already verified after transporter creation)

- added template loading from server/src/assets
	* special email html for readability across multiple mail clients
	* expressions inside {{}} are replaced by the values of the replace argument in the sendMail function
	* templates are both in txt and html for mail clients that don't support html