Add dummy sentry.properties file for easier building

[shaz01]

Currently, the sentry plugin is throwing an exception while building because of the lack of sentry.properties file.
My suggestion is to add a dummy sentry.properties file in the root folder:

defaults.url=
defaults.org=
defaults.project=
auth.token=
sentry.dsn=
sentry.auth.token=

Note that I'm not experienced with sentry, and therefore I might've added unneccessary fields.