Support for chance-generator

package.json

@@ -22,6 +22,7 @@
     "z-schema": "^3.1.3"
   },
   "dependencies": {
+    "chance": "^0.6.4",
     "deref": "^0.2.5",
     "faker": "^2.1.0",
     "randexp": "^0.4.0"

spec/core/types/strings.json

@@ -78,6 +78,29 @@
           "required": ["name", "email"]
         },
         "valid": true
+      },
+      {
+        "description": "should handle format (chance)",
+        "schema": {
+          "type": "object",
+          "properties": {
+            "userId": {
+              "type": "string",
+              "chance": "guid"
+            },
+            "emailAddr": {
+              "type": "string",
+              "chance": {
+                "email": {
+                  "domain": "fake.com"
+                }
+              },
+              "pattern": ".+@fake.com"
+            }
+          },
+          "required": ["userId", "emailAddr"]
+        },
+        "valid": true
       }
     ]
   }