fix(template): Fix jest bugs in react template

[FDiskas]

This pull request closes issue # (put the issue number here)

Current state

npm init hops-app my-hops-app
cd my-hops-app
npm test

Requires Babel "^7.0.0-0", but was loaded with "6.26.3". If you are sure you have a compatible version of @babel/core, it is likely that something in your build process is loading th
e wrong version. Inspect the stack trace of this error to look for the first entry that doesn't mention "@babel/core" or "babel-core" to see what is calling Babel.

Changes introduced here

How to fix:
npx babel-upgrade --write --install
npm audit fix --force

NOTE And commit pakage-lock.json or yarn.lock to git for keeping versions locked and not introduce unexpected errors for end users

Checklist

• All commit messages adhere to the appropriate format in order to trigger a correct release
• All code is written in untranspiled ECMAScript (ES 2017) and is formatted using prettier
• Necessary unit tests are added in order to ensure correct behavior
• Documentation has been added

[ZauberNerd]

Also on another note: Could you please apply this fix to hops-template-graphql and hops-template-redux as well?
And, while you are at it, could you please reword the commit message to something like: fix(template-react): add babel-core as dev dependency (and fix(template-graphql): and fix(template-redux): for the others)?

[ZauberNerd]

I would prefer to remove babel-jest here, because we have it already as a dependency in the jest-preset-hops:
https://github.com/xing/hops/blob/master/packages/jest-preset/package.json#L31

Also, I would like to keep jest at version 23 for now, because unfortunately we still have some discussion points open, for how we could upgrade to jest 24 without being breaking for our users (see #815 and https://github.com/xing/hops/pulls?q=is%3Apr+is%3Aopen+label%3Ablocked)

I will try to raise this topic to our attention and investigate if we can find a solution where we can safely upgrade to jest 24, but until then we should stay at 23 to be on the safe side.

So in a nutshell: It will be enough to just add babel-core@7.0.0-bridge.0 to the dev dependencies ;)

[ZauberNerd]

Hi @FDiskas do you want to continue on this PR or should we take over and implement this ourselves?

[FDiskas]

Yes please. I'm gone for holiday

[ZauberNerd]

@FDiskas I continued your PR here: #887