Updated README for SecondConf
Updated Code of Conduct for SecondConf

- Replaced references to PyCon with SecondConf
- Removed references to an exhibit hall and vendor booths
- Updated contact names and phone numbers for SecondConf
Updated attendee procedure for incident handling

- Changed PyCon to SecondConf
- Removed mention of STAFF t-shirt button, added lanyard
- Changed contact information for SecondConf
- Changed mentions of "hotel" to "venue"
Updated staff procedure for incident handling

- Removed mention of badge number, added Twitter handle
- Changed PyCon to SecondConf
- Changed contact information for SecondConf