Accept Array type on verification and creation.

[lbalmaceda]

Now we can specify Arrays of type String or Integer for creation/verification of JWTs.

1. Get a Claim as a custom class:

Claim claim = jwt.getClaim("user");
UserProfile user = claim.as(UserProfile.class);

2. Create a token with an Array Claim:

String jwt = JWTCreator.init()
                .withArrayClaim("name", new String[]{"a", "b", "c"})
                .sign(Algorithm.HMAC256("secret"));

3. Verify that a token contains an Array Claim with at least specific items:

DecodedJWT jwt = JWTVerifier.init(Algorithm.HMAC256("secret"))
                .withArrayClaim("name", "a", "b")
                .build()
                .verify(token);

Note that in this example, UserProfile class must have a no-args public constructor for deserialization to work.

[lbalmaceda]

Adds the features discussed in #117