[-] Technical - Upgrade to babel 7 stable

[rap2hpoutre]

Pull Request checklist:

• Write an explicit title for the Pull Request
• Write changes made in the CHANGELOG.md
• Create automatic tests
• Test manually the implemented changes
• Review my own code (indentation, syntax, style, simplicity, readability)
• Wonder if you can improve the existing code

[rap2hpoutre]

Broken. See:

• Template string failing with Cannot read property 'range' of null babel/babel-eslint#799
• Cannot read property 'range' of null babel/babel-eslint#681
• TypeError: Cannot read property 'range' of null from template-curly-spacing babel/babel-eslint#530

Edit: fixed with yarn upgrade (we use exact versions in dependencies, it should be ≈safe).

[VincentMolinie]

Same thing it works perfectly but the yarn.lock is not up to date

[rap2hpoutre]

Fixed thanks!!