Add fallback for tsconfig api

- pick from vuejs#246

Author: nogic1008

Diff for: lib/utils.js

@@ -66,9 +66,10 @@ const getBabelOptions = function loadBabelOptions(filename, options = {}) {
 const getTsJestConfig = function getTsJestConfig(config) {
   const createTransformer = require('ts-jest').createTransformer
   const tr = createTransformer()
-  const { typescript } = tr.configsFor(config)
+  const configSet = tr.configsFor(config)
+  const tsConfig = configSet.typescript || configSet.parsedTsConfig
   // Force es5 to prevent const vue_1 = require('vue') from conflicting
-  return { compilerOptions: { ...typescript.options, target: 'es5' } }
+  return { compilerOptions: { ...tsConfig.options, target: 'es5' } }
 }
 
 function isValidTransformer(transformer) {