title: travis cannot build because Error: Cannot find module 'react-test-renderer/shallow'
body: <p>The <code>npm run test</code> works fine locally. </p>
  
  <p>However , travis insists that the build is failed and it shows the following log : </p>
  
  <pre><code>react-test-renderer is an implicit dependency in order to support react@15.5+. Please add the appropriate version to your devDependencies. See https://github.com/airbnb/enzyme#installation
  No coverage information was collected, exit without writing coverage information
  /home/travis/build/abdennour/react-csv/node_modules/enzyme/build/react-compat.js:159
        throw e;
        ^
  Error: Cannot find module 'react-test-renderer/shallow'
      at Function.Module._resolveFilename (module.js:469:15)
      at Function.Module._load (module.js:417:25)
      at Module.require (module.js:497:17)
      at require (internal/module.js:20:19)
      at /home/travis/build/abdennour/react-csv/node_modules/enzyme/build/react-compat.js:151:34
      at Object.&lt;anonymous&gt; (/home/travis/build/abdennour/react-csv/node_modules/enzyme/build/react-compat.js:219:5)
  </code></pre>
  
  <p>Any idea ? known that my dependencies are : </p>
  
  <pre><code>  "devDependencies": {
      "babel-cli": "^6.18.0",
      "babel-core": "^6.18.2",
      "babel-istanbul": "^0.11.0",
      "babel-loader": "^6.2.8",
      "babel-plugin-react-html-attrs": "^2.0.0",
      "babel-plugin-syntax-decorators": "^6.13.0",
      "babel-plugin-transform-class-properties": "^6.19.0",
      "babel-plugin-transform-decorators-legacy": "^1.3.4",
      "babel-plugin-transform-es2015-modules-commonjs": "^6.18.0",
      "babel-polyfill": "^6.16.0",
      "babel-preset-es2015": "^6.18.0",
      "babel-preset-react": "^6.16.0",
      "babel-preset-stage-3": "^6.16.0",
      "browserify": "^13.3.0",
      "console-info": "0.0.4",
      "coveralls": "^2.11.15",
      "css-loader": "^0.26.1",
      "enzyme": "^2.6.0",
      "expect": "^1.20.2",
      "extract-text-webpack-plugin": "^1.0.1",
      "isparta-loader": "^2.0.0",
      "jsdom": "9.8.3",
      "jsdom-global": "2.1.0",
      "mocha": "^3.2.0",
      "mocha-lcov-reporter": "^1.2.0",
      "react": "^15.4.1",
      "react-addons-test-utils": "^15.4.1",
      "react-docgen": "^2.13.0",
      "react-dom": "^15.4.1",
      "react-styleguidist": "^4.6.3",
      "sass-loader": "^4.0.2",
      "sinon": "^1.17.6",
      "style-loader": "^0.13.1",
      "uglify-js": "^2.7.5",
      "webpack": "^1.13.3",
      "webpack-dev-middleware": "^1.8.4",
      "webpack-dev-server": "^1.16.2",
      "webpack-hot-middleware": "^2.13.2"
  </code></pre>