Micro-Benchmarking Scala Maps

Using Caliper and Scala 2.11.6.

Results

For maps with 100, 1000, and 10000 elements (lower is better):

![graph] (src/R/plot.png)

Map implementations:

java.util.concurrent.HashMap
java.util.HashMap
java.util.TreeMap
scala.collection.immutable.HashMap
scala.collection.immutable.IntMap
scala.collection.immutable.LongMap
scala.collection.immutable.TreeMap
scala.collection.mutable.HashMap
scala.collection.mutable.LinkedHashMap
scala.collection.mutable.LongMap
scala.collection.mutable.ListMap
scala.collection.mutable.OpenHashMap