Add Travis for created apps

[Jiansen]

In addition to local Jest test, I think it is still useful to include .travis.yml in the generated app. For example, like CRA, the app could be built and tested in both Node 4 and 6 for every pushed commit.

Travis is harmless for users who don't want to use it.

[ryanyogan]

You are correct on CRA using travis: https://github.com/facebookincubator/create-react-app/blob/master/.travis.yml as an open source project.

I think it would be a tad too opinionated to push a CI service on an individual as there are many other providers. Travis is awesome for open source however many tend to utilize other services due to the cost of Travis for personal projects.

Just my .02

[gaearon]

Yea, we won't be doing this. You can always add it yourself, and it's indeed too opinionated. Thanks for the suggestion though!

[vjeux]

@gaearon would be nice to put an entry in the readme on how to setup travis. Should be pretty easy

[gaearon]

Agree now that we have testing.
@Jiansen Would you like to work on a PR adding this doc note?

[rogeliog]

@vjeux I like the idea of a CI section, where it could eventually show how to setup different CI services(similar to the deployment section). I'm more than happy to help with this one :)

[rogeliog]

Oops sorry :( I posted my comment a minute after @gaearon... If @Jiansen is planning on working on this then that sounds great also! :) :)

[gaearon]

@rogeliog Issue is pretty old so I think it’s fine if you take it. 👍 If @Jiansen is also interested, they can express their interest here later and maybe collaborate.

[Jiansen]

@gaearon , I am happy to adding Travis set up process to a doc note.

@rogeliog , if you wanted to take it and/or add process of setting up other CIs, I am sure it will be very useful for some users. Just let me know if you may want me to work on the note for Travis.

[rogeliog]

@Jiansen, yeah, if you want to add the note for Travis I think that it makes sense and you should take it 😄 that is more than fine with me 👍 We can worry about adding notes for other CIs when the need comes :)