Deserialize payload into dictionary

JotTests/JotTests.swift

@@ -21,4 +21,15 @@ class JotTests: XCTestCase {
         XCTAssertEqual(jwt.header.typ, JwtType.jwt)
     }
     
+    func testJWTPayload() {
+        guard let jwt = JWT(token:  "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJqZ3JpZmZpbiIsIm5hbWUiOiJKYW1lcyBHcmlmZmluIiwiYWRtaW4iOnRydWUsImlhdCI6MTUxNjIzOTAyMn0.DXfNW7Gzvie7LIl5-HSG9clm3sjeglYG2uNmsPvcNerBQbzLI06vys4YqqCMtrWKEFij_y2hKGP9YFdHSRMdtyVcGEXmYP6H6E62uGhASmGFzEHeSa6B1X1-v8lRt_YpIGEXhkUnxfhdcQ90HJlNfajv0ndnRFk8YJxRkmr99OI") else {
+            XCTFail()
+            return
+        }
+        
+        XCTAssertEqual(jwt.payload["sub"] as? String, "jgriffin")
+        XCTAssertEqual(jwt.payload["name"] as? String, "James Griffin")
+        
+    }
+    
 }