opportunity: Added maybe option

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
opportunity: Various bugfixes on Model

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
opportunity: Added count and score to Meetup display page

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
opportunity: Security update, blocks XSS injections.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
opportunity: Tests update for new DB model

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>