Update include paths and initialize rack tracing.
Update include paths and initialize rack tracing.

appneta/ruby-traceview,appneta/ruby-traceview,boyang-li/oboe-ruby,tlunter/oboe-ruby,tlunter/oboe-ruby,boyang-li/oboe-ruby,tlunter/oboe-ruby,tlunter/oboe-ruby,appneta/ruby-traceview,appneta/ruby-traceview,boyang-li/oboe-ruby,boyang-li/oboe-ruby