Issue on installation

Hi !

On installation, i have an error

/home/website/node_modules/babel-plugin-transform-react-jsx/lib/index.js:14
  var visitor = require("babel-helper-builder-react-jsx")({ /*istanbul ignore next*/
                                                         ^

TypeError: require(...) is not a function
    at exports.default (index.js:14:17)
    at Function.memoisePluginContainer (/home/website/node_modules/babel-core/lib/transformation/file/options/option-manager.js:150:13)
    at Function.normalisePlugin (/home/website/node_modules/babel-core/lib/transformation/file/options/option-manager.js:184:32)
    at /home/website/node_modules/babel-core/lib/transformation/file/options/option-manager.js:224:30
    at Array.map (native)
    at Function.normalisePlugins (/home/website/node_modules/babel-core/lib/transformation/file/options/option-manager.js:196:20)
    at OptionManager.mergeOptions (/home/website/node_modules/babel-core/lib/transformation/file/options/option-manager.js:317:36)
    at /home/website/node_modules/babel-core/lib/transformation/file/options/option-manager.js:389:38
    at /home/website/node_modules/babel-core/lib/transformation/file/options/option-manager.js:410:24
    at Array.map (native)
website@1.0.0 /home/website
└── babel-helpers@6.8.0

npm WARN optional Skipping failed optional dependency /chokidar/fsevents:
npm WARN notsup Not compatible with your operating system or architecture: fsevents@1.0.12
npm ERR! Linux 3.14.32-xxxx-std-ipv6-64
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "install"
npm ERR! node v4.4.1
npm ERR! npm  v3.8.3
npm ERR! code ELIFECYCLE

npm ERR! slackin@0.8.3 postinstall: `gulp`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the slackin@0.8.3 postinstall script 'gulp'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the slackin package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     gulp
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!     npm bugs slackin
npm ERR! Or if that isn't available, you can get their info via:
npm ERR!     npm owner ls slackin
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:
npm ERR!     /home/website/npm-debug.log

> website@1.0.0 build /home/website
> webpack --config webpack/prod.config.js

If i test with slackin@0.7.3 is ok

[AIexey-L]

this one is working (at least by Heroku) —> https://github.com/rauchg/slackin/issues/160

[webwurst]

@AnsgarSchmidt Your issue could maybe be solved by adding --unsafe-perm to npm install as seen in the Dockerfile.