Issue with bcrypt, node-gyp on Travis

[heron2014]

Error on building Travis:

Solution:

• travis.yml

sudo: false
env:
  - CXX=g++-4.8
language: node_js
node_js:
  - "4"
addons:
  apt:
    sources:
    - ubuntu-toolchain-r-test
    packages:
    - gcc-4.8
    - g++-4.8