Fix babel target to es5

[ysgk]

close #329

This PR fixes the babel target so that it works on legacy browsers.

[blainekasten]

@ysgk sorry for the delay here. CI seems goofed up. Going to get that re-configured before we merge

[boygirl]

@blainekasten I just migrated a bunch of repos from gh services based travis CI to gh apps based travis CI. This PR doesn't show up in either build history. I think it may be necessary to push a fresh commit or open these changes in a new PR to trigger CI

[ljharb]

@boygirl you can also manually trigger a PR build, i believe, in travis' interface

[boygirl]

@ljharb normally I would be able to, but this branch does not show up in the buid history either on the new or old interface. It isn't that it errored, it never triggered at all.

[ljharb]

@boygirl i don't mean rerun it - i mean there's a beta "trigger build" feature under "more options".

[boygirl]

@ljharb but unfortunately this branch was never recognized by travis for whatever reason, so I am not able to trigger a build for it:

It is not included in the list of branches for this repo

[ysgk]

I merged master. Now CI runs but fails.

https://github.com/FormidableLabs/enzyme-matchers/blob/48295d2b2730232a930125d3fc68235214261b88/packages/jest-environment-enzyme/src/index.js#L3

JSDOMEnvironment is exported from jest-environment-dom as an es6 class, so this line complains:

TypeError: Class constructor JSDOMEnvironment cannot be invoked without 'new'

I tried transformIgnorePatterns to transform jest-environment-dom, but didn't work. Are there any solutions for that?

[ljharb]

@ysgk it'd be really great if you could restore this branch and reopen the PR; there's still hope to merge it.

[ysgk]

@ljharb OK, done :)