fix: explicitly set the parser to babylon

Avoid the `ImportExpression` error in older versions of ast-types &
recast.

Author: haoqunjiang

generator/codemods/global-api/index.js

@@ -21,3 +21,4 @@ module.exports = function(fileInfo, api) {
   return root.toSource({ lineTerminator: '\n' })
 }
 
+module.exports.parser = 'babylon'

generator/codemods/router/index.js

@@ -61,3 +61,5 @@ module.exports = function(fileInfo, api) {
 
   return root.toSource({ lineTerminator: '\n' })
 }
+
+module.exports.parser = 'babylon'

generator/codemods/vuex/index.js

@@ -65,3 +65,5 @@ module.exports = function(fileInfo, api) {
 
   return root.toSource({ lineTerminator: '\n' })
 }
+
+module.exports.parser = 'babylon'