Update from upstream repo facebookincubator/create-react-app#1

Merged

paweljedrzejczyk merged 10 commits intopaweljedrzejczyk:masterfrom

facebook:master

Jun 12, 2017

Commits on Jun 2, 2017

Update Travis CI Node versions in User Guide (#2454)

ryansully
authored and
gaearon
committed

Commits on Jun 4, 2017

re-add storybook && update the documentation and links (#2331)

ndelangen
authored and
Timer
committed

Commits on Jun 5, 2017

Prioritize index.css over the implicit App.css (#2470)

bryankang
authored and
gaearon
committed

Commits on Jun 6, 2017

Added NamedModulesPlugin in webpack.config.dev.js (#2458)

Zaccc123
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gaearon
committed
Unscope detect-port (#2483)
Timer
authored

Commits on Jun 7, 2017

Update webpack links to point to webpack 2 (#2492)

Stanislas Ormières
authored and
gaearon
committed
chore(templates): Move GitHub templates to hidden .github folder (#2489)

glennreyes
authored and
gaearon
committed

Commits on Jun 8, 2017

Fix minor docs typo (#2500)

AlexxNica
authored and
Timer
committed

Commits on Jun 12, 2017

Fix link to Storybook docs (#2521)

shilman
authored and
Timer
committed
Simplify flow init docs (#2522)

khanglu
authored and
Timer
committed