Add Benchmarks via Caliper

A template for the build file:

https://github.com/twitter/bijection/blob/feature/bijection-bench/project/Build.scala#L219

And for the benchmarks:

https://github.com/twitter/bijection/blob/feature/bijection-bench/bijection-bench/src/main/scala/com/twitter/bijection/bench/Benchmark.scala#L44

Map Benchmark template:

https://github.com/non/debox/blob/master/benchmark/src/main/scala/debox/benchmark/MapBenchmark.scala