Feature/fix ie11 buble

[lukenofurther]

Fixes issue #158, as suggested in this vue-styleguidist issue.

Note that the first commit simply commits changes that appear in package-lock.json after running the initial npm install.

[nplowman]

Adding a note for anyone else who encountered this:

I found that I had to include acorn-jsx like this:
resolve("node_modules/acorn-jsx"),
rather than like this:
resolve("node_modules/buble/node_modules/acorn-jsx"),
for it to work.

I think whether or not you have the nested node_module paths might depend on the version of node you are using.

[arapd]

This issue is essential to work with IE11. Is there a plan to merge this PR and release a version soon?