Testing Flashes. Way more optimized session handling.

Benchmark breakdown

Master:
BenchmarkNoSessionsMiddleware     500000              5371 ns/op
BenchmarkSessionsNoWrites         100000             27558 ns/op
BenchmarkSessionsWithWrite         50000             31802 ns/op
BenchmarkSessionsWithRead         100000             26393 ns/op

JMS-38:
BenchmarkNoSessionsMiddleware     500000              5064 ns/op
BenchmarkSessionsNoWrites         200000              7481 ns/op
BenchmarkSessionsWithWrite         50000             31810 ns/op
BenchmarkSessionsWithRead         200000             10483 ns/op

closes #37 
closes #38