Merge pull request #19 from spencersutton/master

Example in readme panics.

README.md

@@ -29,12 +29,12 @@ Basic Example
 -------------
 
 ```go
-vm := New()
+vm := goja.New()
 v, err := vm.RunString("2 + 2")
 if err != nil {
     panic(err)
 }
-if num := v.Export(); num != 4 {
+if num := v.Export().(int64); num != 4 {
     panic(num)
 }
 ```