Does not work on OS X / node 5.10 / npm 3.8.3

After `npm start` I'm getting:

```
0 info it worked if it ends with ok
1 verbose cli [ '/usr/local/bin/node', '/usr/local/bin/npm', 'start' ]
2 info using npm@3.8.3
3 info using node@v5.10.0
4 verbose run-script [ 'prestart', 'start', 'poststart' ]
5 info lifecycle dropfox@1.0.0~prestart: dropfox@1.0.0
6 silly lifecycle dropfox@1.0.0~prestart: no script for prestart, continuing
7 info lifecycle dropfox@1.0.0~start: dropfox@1.0.0
8 verbose lifecycle dropfox@1.0.0~start: unsafe-perm in lifecycle true
9 verbose lifecycle dropfox@1.0.0~start: PATH: /usr/local/lib/node_modules/npm/bin/node-gyp-bin:/Users/maxmilovanov/projects/demoes/dropfox/node_modules/.bin:/usr/local/bin:/usr/local/lib/dnx/runtimes/dnx-coreclr-darwin-x64.1.0.0-rc1-final/bin:/Users/maxmilovanov/.dnx/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/share/dotnet/bin:/usr/local/git/bin:/usr/local/go/bin:/Users/maxmilovanov/go/bin
10 verbose lifecycle dropfox@1.0.0~start: CWD: /Users/maxmilovanov/projects/demoes/dropfox
11 silly lifecycle dropfox@1.0.0~start: Args: [ '-c',
11 silly lifecycle 'ENV=dev parallelshell \'npm run dev\' \'npm run thenelectron\'' ]
12 silly lifecycle dropfox@1.0.0~start: Returned: code: 1 signal: null
13 info lifecycle dropfox@1.0.0~start: Failed to exec start script
14 verbose stack Error: dropfox@1.0.0 start: `ENV=dev parallelshell 'npm run dev' 'npm run thenelectron'`
14 verbose stack Exit status 1
14 verbose stack at EventEmitter. (/usr/local/lib/node_modules/npm/lib/utils/lifecycle.js:239:16)
14 verbose stack at emitTwo (events.js:100:13)
14 verbose stack at EventEmitter.emit (events.js:185:7)
14 verbose stack at ChildProcess. (/usr/local/lib/node_modules/npm/lib/utils/spawn.js:24:14)
14 verbose stack at emitTwo (events.js:100:13)
14 verbose stack at ChildProcess.emit (events.js:185:7)
14 verbose stack at maybeClose (internal/child_process.js:850:16)
14 verbose stack at Process.ChildProcess._handle.onexit (internal/child_process.js:215:5)
15 verbose pkgid dropfox@1.0.0
16 verbose cwd /Users/maxmilovanov/projects/demoes/dropfox
17 error Darwin 15.4.0
18 error argv "/usr/local/bin/node" "/usr/local/bin/npm" "start"
19 error node v5.10.0
20 error npm v3.8.3
21 error code ELIFECYCLE
22 error dropfox@1.0.0 start: `ENV=dev parallelshell 'npm run dev' 'npm run thenelectron'`
22 error Exit status 1
23 error Failed at the dropfox@1.0.0 start script 'ENV=dev parallelshell 'npm run dev' 'npm run thenelectron''.
23 error Make sure you have the latest version of node.js and npm installed.
23 error If you do, this is most likely a problem with the dropfox package,
23 error not with npm itself.
23 error Tell the author that this fails on your system:
23 error ENV=dev parallelshell 'npm run dev' 'npm run thenelectron'
23 error You can get information on how to open an issue for this project with:
23 error npm bugs dropfox
23 error Or if that isn't available, you can get their info via:
23 error npm owner ls dropfox
23 error There is likely additional logging output above.
24 verbose exit [ 1, true ]
```

Start with the npm start script shown in the error and reproduce it on the reported OS X, Node 5.10.0, and npm 3.8.3 environment. Trace the failing start command, `ENV=dev parallelshell 'npm run dev' 'npm run thenelectron'`; done means `npm start` launches successfully without the lifecycle error.

Scritto dal modello di indicizzazione a partire dal testo della issue.