• updated signal-cli to version 0.7.2
• added health endpoint - used by the docker daemon to perform health checks (see #63)
• added endpoint to the update profile
• added endpoint to query attachments (see #52)
• fixed bug that prevented to create a new Signal group (see #54)
• fixed some markdown formatting issues (thanks to @x-jokay)
• added docker container health checks (thanks to @x-jokay)
• change base docker image to reduce docker image size (thanks to @x-jokay)
• added possibility to specify captcha in register endpoint (see #19)