Hi,
On our project we would like to use this module. Unfortunately there were some broken dependencies.

This PR:

• replace the com.sun.mail package with the org.eclipse.angus one
• update the README.md with the new dependencies to add to the olog's pom.xml
• sort imports
• add support for attachments as requested in Include attachments in email #2 (it is an interesting feature)
• add tests on the attachment section
• prepend "[]" in the email's subject
• update the version from 1.0 to 1.2.0

I'm not a Java developer and, since this version currently works as it is for our use case, if changes are needed, we would appreciate them coming directly from the main developers.

Regards,
Giovanni

PS a side note regarding the attachments improvement. A fix on the olog service is needed. In fact, when sending the data to the email-notifier, the olog-service does not add the attachments. The email notifier still works but the attchments are missing. I already implemented a fix on this behavior (on top of v5.1.2) on my fork https://github.com/giosava94/phoebus-olog (branch fix-notify-with-attachment).