SIN should call EncodedData constructor

Creating SINs was broken due to not calling the parent constructor, shich sets
"converts" and "_encoding". I've fixed the problem and added tests that reveal
the error.

lib/SIN.js

@@ -3,10 +3,9 @@ var EncodedData = require('../util/EncodedData');
 var util = require('util');
 
 function SIN(type, payload) {
-  if (typeof type != 'number') {
-    SIN.super_.call(this, type, payload);
+  SIN.super_.call(this, type, payload);
+  if (typeof type != 'number')
     return;
-  };
   this.data = new Buffer(1 + 1 + payload.length);
   this.encoding('binary');
   this.prefix(0x0F); // SIN magic number, in numberspace

test/test.SIN.js

@@ -33,6 +33,14 @@ describe('SIN', function() {
       s.should.equal(a.toString()); // check that validation doesn't change data
     });
   });
+
+  describe('#SIN', function() {
+    it('should be able to create a new SIN with a version byte', function() {
+      var myhash = bitcore.util.sha256ripe160('test');
+      var sin = new SIN(SIN.SIN_EPHEM, myhash);
+      should.exist(sin);
+    });
+  });
 });
 
 

test/test.SINKey.js

@@ -4,16 +4,11 @@ var chai = chai || require('chai');
 var bitcore = bitcore || require('../bitcore');
 var should = chai.should();
 
-var SINKeyModule = bitcore.SINKey;
-var SINKey;
+var SINKey = bitcore.SINKey;
 
 
 describe('SINKey', function() {
   it('should initialze the main object', function() {
-    should.exist(SINKeyModule);
-  });
-  it('should be able to create class', function() {
-    SINKey = SINKeyModule;
     should.exist(SINKey);
   });
   it('should be able to create instance', function() {
@@ -24,4 +19,13 @@ describe('SINKey', function() {
     should.exist(sk.privKey.public);
     should.exist(sk.privKey.compressed);
   });
+
+  describe('#storeObj', function() {
+    it('should give an object', function() {
+      var sinkey = new SINKey();
+      sinkey.generate();
+      var obj = sinkey.storeObj();
+      should.exist(obj);
+    });
+  });
 });