Support passing in a Buffer to a Binary type.

Also updates Joi to the latest version as it seems that the version originally set does not seem to support a set having multiple types (as would be the case in a BinarySet here the values can either be Buffers or Strings).
Fixes
Merge branch 'master' into feature/binary-buffer-support

Conflicts:
	lib/schema.js
	lib/serializer.js
	package.json
	test/schema-test.js
Fixed case on "Binary"
Merge pull request #23 from Sazpaimon/feature/binary-buffer-support

Support Binary as Buffer