add main class to pom
Close the RandomAccessFile instance to prevent IO Exceptions.

large numbers of files being scanned would yield
Exception in thread "main" java.io.FileNotFoundException: <redacted> (Too many open files)
	at java.io.RandomAccessFile.open(Native Method)
	at java.io.RandomAccessFile.<init>(RandomAccessFile.java:241)
	at silly.metrics.KeywordCounter.recurse(KeywordCounter.java:222)
	at silly.metrics.KeywordCounter.recurse(KeywordCounter.java:218)
	at silly.metrics.KeywordCounter.recurse(KeywordCounter.java:218)
Merge pull request #1 from jwadamson/master

Two quick things