Node 8.x.x Support

[pethin]

Bug

@dojo/test-extras does not support NodeJS LTS Carbon

Package Version: 2.0.0

Code

$ yarn install

Expected behavior:

yarn install v1.6.0
warning package.json: No license field
info No lockfile found.
warning first-dojo-2-app@1.0.0: No license field
[1/4] Resolving packages...
warning @dojo/cli-build-app > @theintern/istanbul-loader > @types/source-map@0.5.7: This is a stub types definition for source-map (https://github.com/mozilla/source-map). source-map provides its own type definitions, so you don't need @types/source-map installed!
warning @dojo/cli-test-intern > sinon > formatio@1.1.1: This package is unmaintained. Use @sinonjs/formatio instead
warning @dojo/cli-test-intern > intern > @dojo/interfaces@0.2.1: @dojo/interfaces is deprecated
warning @dojo/cli-test-intern > intern > @theintern/digdug > @dojo/interfaces@0.2.1: @dojo/interfaces is deprecated
warning @dojo/cli-test-intern > intern > @theintern/leadfoot > @dojo/interfaces@0.2.1: @dojo/interfaces is deprecated
warning @dojo/cli-test-intern > codecov.io > request > node-uuid@1.4.8: Use uuid module instead
[2/4] Fetching packages...
info fsevents@1.2.3: The platform "win32" is incompatible with this module.
info "fsevents@1.2.3" is an optional dependency and failed compatibility check. Excluding it from installation.
[3/4] Linking dependencies...
warning "@dojo/cli-build-app > postcss-cssnext@3.0.2" has unmet peer dependency "caniuse-lite@^1.0.30000697".
warning "@dojo/cli-build-app > @theintern/istanbul-loader@1.0.0-beta.1" has incorrect peer dependency "webpack@^2.0.0".
warning "@dojo/cli-build-app > @theintern/istanbul-loader@1.0.0-beta.1" has unmet peer dependency "istanbul-lib-instrument@^1.0.0".
[4/4] Building fresh packages...
success Saved lockfile.
Done in 18.77s.

Actual behavior:

yarn install v1.6.0
warning package.json: No license field
info No lockfile found.
warning first-dojo-2-app@1.0.0: No license field
[1/4] Resolving packages...
warning @dojo/cli-build-app > @theintern/istanbul-loader > @types/source-map@0.5.7: This is a stub types definition for source-map (https://github.com/mozilla/source-map). source-map provides its own type definitions, so you don't need @types/source-map installed!
warning @dojo/cli-test-intern > sinon > formatio@1.1.1: This package is unmaintained. Use @sinonjs/formatio instead
warning @dojo/cli-test-intern > codecov.io > request > node-uuid@1.4.8: Use uuid module instead
warning @dojo/cli-test-intern > intern > @dojo/interfaces@0.2.1: @dojo/interfaces is deprecated
warning @dojo/cli-test-intern > intern > @theintern/digdug > @dojo/interfaces@0.2.1: @dojo/interfaces is deprecated
warning @dojo/cli-test-intern > intern > @theintern/leadfoot > @dojo/interfaces@0.2.1: @dojo/interfaces is deprecated
[2/4] Fetching packages...
info fsevents@1.2.3: The platform "win32" is incompatible with this module.
info "fsevents@1.2.3" is an optional dependency and failed compatibility check. Excluding it from installation.
error @dojo/test-extras@2.0.0: The engine "node" is incompatible with this module. Expected version "^6.0.0 || ^7.0.0".
error Found incompatible module
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.