Update acorn to version 3.0.0 🚀

Hello :wave:

:rocket::rocket::rocket:

acorn just published its new version 3.0.0, which is not covered by your current version range.

If this pull request passes your tests you can publish your software with the latest version of acorn – otherwise use this branch to work on adaptions and fixes.

Happy fixing and merging :palm_tree:

The new version differs by 18 commits .

a31a904 Mark version 3.0.0
ba6a038 Clean up parsing of unary and binary expressions
0828665 Drop unused import
df8febd Adjust parsing of exponentation expression
a8ce3a1 Add support for ** under ecmaVersion 7
bed0042 Make 6 the default for the ecmaVersion option
0453696 Parse default-exported parenthesized classes/functions correctly
4593dc8 Add raiseRecoverable hook
4780db5 Speed up generate-identifier-regex
3513639 Correct and remove outdated comment in identifier
347ff8b Update to unicode-8.0.0
5d9fd25 generate-identifier-regex: Adapt to new source syntax
0aab0be Update license year range to 2016
c91474a Remove some semicolons
d1474ae Remove support for comprehension

There are 18 commits in total. See the full diff.

This pull request was created by greenkeeper.io. It keeps your software, up to date, all the time.

_{Tired of seeing this sponsor message? Upgrade to the supporter plan!
You'll also get your pull requests faster :zap:}

babel / kneden

Update acorn to version 3.0.0 🚀 #14