output log in JSON format for graph generation
output log in JSON format for graph generation

- not yet capturing server_time correctly
- log file is still hardcoded

… and yes, I'm hand-writing JSON. I want it to write out (streaming) as data is available rather than generating a big object in memory and I didn't feel like using Jackson for such simple JSON.

Netflix-Skunkworks/WSPerfLab,Netflix-Skunkworks/WSPerfLab,Netflix-Skunkworks/WSPerfLab