Add SimpleFlatMapper and jmh benchmark

I added the jmh benchmark for jackson, opencsv, univocity and simpleflatmapper.
I added a readme in src/main/java/com/univocity/articles/jmh that contains explanation on how to run the jmh. The maven needs to compile so I added the dependency def for 

+	<dependency>
+		<groupId>org.ostermiller</groupId>
+		<artifactId>utils</artifactId>
+		<version>1.07.00</version>
+	</dependency>

only version I could find.

Regards, Arnaud