title: npm start givin error
body: <p>I am building a project with react (Downloaded project using git) and have recently encountered the following error when running</p>
  
  <p>npm start</p>
  
  <p>The error is</p>
  
  <pre><code>enter code here
  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@5.4.2
  3 info using node@v8.7.0
  4 verbose run-script [ 'prestart', 'start', 'poststart' ]
  5 info lifecycle @~prestart: @
  6 info lifecycle @~start: @
  7 verbose lifecycle @~start: unsafe-perm in lifecycle true
  8 verbose lifecycle @~start: PATH: /usr/local/lib/node_modules/npm/bin/node-gyp-bin:/home/ambuj/Documents/react-weather-app/node_modules/.bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin:/snap/bin
  9 verbose lifecycle @~start: CWD: /home/ambuj/Documents/react-weather-app
  10 silly lifecycle @~start: Args: [ '-c', 'concurrently "yarn serve:webpack" "yarn serve:json"' ]
  11 silly lifecycle @~start: Returned: code: 1  signal: null
  12 info lifecycle @~start: Failed to exec start script
  13 verbose stack Error: @ start: `concurrently "yarn serve:webpack" "yarn serve:json"`
  13 verbose stack Exit status 1
  13 verbose stack     at EventEmitter.&lt;anonymous&gt; (/usr/local/lib/node_modules/npm/node_modules/npm-lifecycle/index.js:280:16)
  13 verbose stack     at emitTwo (events.js:125:13)
  13 verbose stack     at EventEmitter.emit (events.js:213:7)
  13 verbose stack     at ChildProcess.&lt;anonymous&gt; (/usr/local/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:55:14)
  13 verbose stack     at emitTwo (events.js:125:13)
  13 verbose stack     at ChildProcess.emit (events.js:213:7)
  13 verbose stack     at maybeClose (internal/child_process.js:927:16)
  13 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:211:5)
  14 verbose pkgid @
  15 verbose cwd /home/ambuj/Documents/react-weather-app
  16 verbose Linux 4.10.0-19-generic
  17 verbose argv "/usr/local/bin/node" "/usr/local/bin/npm" "start"
  18 verbose node v8.7.0
  19 verbose npm  v5.4.2
  20 error code ELIFECYCLE
  21 error errno 1
  22 error @ start: `concurrently "yarn serve:webpack" "yarn serve:json"`
  22 error Exit status 1
  23 error Failed at the @ start script.
  23 error This is probably not a problem with npm. There is likely additional logging output above.
  24 verbose exit [ 1, true ]
  </code></pre>