Packaging about gui

[holandes22]

Some progress on travis https://travis-ci.org/holandes22/exercism-gui/builds/137330054

Linux is working and package is being built

OSX is not working. Seems to install all node and bower deps, but when running the package command it fails

$ ember electron:package --platform $TRAVIS_OS_NAME --arch x64
/Users/travis/build.sh: line 45: ember: command not found
The command "ember electron:package --platform $TRAVIS_OS_NAME --arch x64" exited with 127.

Seems is not able to find the ember-cli binary installed in the local node_modules. No idea why. According to travis-ci/travis-ci#2311 node_js should be supported in osx

Did not have time to check appveyor to build for Windows

[holandes22]

This is now working on Linux and Mac. Next steps:

• Make it work on Linux
• Build takes quite a long time, and we'll use the same jobs to run the tests, so to speed things up on daily basis, have them build only on release tags and in master branch.
• Compress (tar.gz for Linux/Mac, zip for Windows) and upload packages to GH