Add support for node >= 8

Building a clean Nuxeo using the main branch I get an error using Node version v8.9.4 and NPM version 5.6.0

When the Node version is v0.12.18 it builds fine.

Error messages:

[INFO] — maven-antrun-plugin:1.7:run (bower-install) @ nuxeo-preview-core —
[INFO] Executing tasks

main:

init:
[exec] events.js:183
[exec] throw er; // Unhandled 'error' event
[exec] ^
[exec]
[exec] Error: sha1-TINTjeH25mDCngoTRGhE96foglk= integrity checksum failed when using sha1: wanted sha1-TINTjeH25mDCngoTRGhE96foglk= but got sha1-ITXW36ejWMBprJsXh3YogihFD/o=. (1532 bytes)
[exec] at Transform.on (/usr/local/lib/node_modules/npm/node_modules/ssri/index.js:275:19)
[exec] at emitNone (events.js:111:20)
[exec] at Transform.emit (events.js:208:7)
[exec] at endReadableNT (_stream_readable.js:1055:12)
[exec] at _combinedTickCallback (internal/process/next_tick.js:138:11)
[exec] at process._tickCallback (internal/process/next_tick.js:180:9)
[exec] events.js:183
[exec] throw er; // Unhandled 'error' event
[exec] ^
[exec]
[exec] Error: sha1-TINTjeH25mDCngoTRGhE96foglk= integrity checksum failed when using sha1: wanted sha1-TINTjeH25mDCngoTRGhE96foglk= but got sha1-ITXW36ejWMBprJsXh3YogihFD/o=. (1532 bytes)
[exec] at Transform.on (/usr/local/lib/node_modules/npm/node_modules/ssri/index.js:275:19)
[exec] at emitNone (events.js:111:20)
[exec] at Transform.emit (events.js:208:7)
[exec] at endReadableNT (_stream_readable.js:1055:12)
[exec] at _combinedTickCallback (internal/process/next_tick.js:138:11)
[exec] at process._tickCallback (internal/process/next_tick.js:180:9)
[exec] npm WARN nuxeo-preview-core@0.0.0 No description
[exec] npm WARN nuxeo-preview-core@0.0.0 No repository field.
[exec] npm WARN nuxeo-preview-core@0.0.0 No license field.
[exec]
[exec] npm ERR! cancel after 1 retries!
[exec]
[exec] npm ERR! A complete log of this run can be found in:
[exec] npm ERR! /Users/pcardoso/.npm/_logs/2018-03-28T16_02_54_677Z-debug.log
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] Nuxeo Preview Core ................................. FAILURE [ 24.203 s]

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-antrun-plugin:1.7:run (bower-install) on project nuxeo-preview-core: An Ant BuildException has occured: The following error occurred while executing this line:
[ERROR] /Users/pcardoso/Dev/projects/nuxeo/nuxeo-features/preview/nuxeo-preview-core/build.xml:22: exec returned: 1
[ERROR] around Ant part ...<ant antfile="/Users/pcardoso/Dev/projects/nuxeo/nuxeo-features/preview/nuxeo-preview-core/build.xml" dir="/Users/pcardoso/Dev/projects/nuxeo/nuxeo-features/preview/nuxeo-preview-core" target="build"></ant>... @ 4:203 in /Users/pcardoso/Dev/projects/nuxeo/nuxeo-features/preview/nuxeo-preview-core/target/antrun/build-main.xml
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException