Supports:
```js
// these all should produce "code;" when generated
template`code;`();
template`${0}`(t.identifier('code'));
template`${'code'}`({ code: t.identifier('code') });
template`${t.identifier('code')}`()
template({})`code`();
```
Remove imports to lodash/assign and replace assign with Object.assign.
The lodash/assign is unnecessary for babel 7 as node >4 has the same
functionality built-in with Object.assign as used here.
This resolve the [issue 5353](https://github.com/babel/babel/issues/5353)
Removed `@flow` annotation from files that don't actually pass Flow check at the moment. These will be added back file by file once the files are properly converted to use Flow.
Closes#3064
I'm extremely stupid and didn't commit as I go. To anyone reading this
I'm extremely sorry. A lot of these changes are very broad and I plan on
releasing Babel 6.0.0 today live on stage at Ember Camp London so I'm
afraid I couldn't wait. If you're ever in London I'll buy you a beer
(or assorted beverage!) to make up for it, also I'll kiss your feet and
give you a back massage, maybe.
