bug #11352 [Maintenance][Travis] Upgrade php memory to 6G (lchrusciel)
bug #11352 [Maintenance][Travis] Upgrade php memory to 6G (lchrusciel)

This PR was merged into the 1.8-dev branch.

Discussion
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| Q               | A
| --------------- | -----
| Branch?         | master
| Bug fix?        | yes
| New feature?    | no
| BC breaks?      | no
| Deprecations?   | no
| Related tickets | 
| License         | MIT

Temporary solution, to make build green again. However, we should take a look into memory consumption in our builds and reduce it. 
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Commits
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8b153725740e77a20bd94ee76e75846049c0e8d9 [Maintenance][Travis] Upgrade php memory to 6G

loic425/Sylius,Sylius/Sylius,GSadee/Sylius,101medialab/Sylius,kayue/Sylius,foobarflies/Sylius,SyliusBot/Sylius,foobarflies/Sylius,mbabker/Sylius,pjedrzejewski/Sylius,mbabker/Sylius,foobarflies/Sylius,foobarflies/Sylius,pamil/Sylius,kayue/Sylius,kayue/Sylius,lchrusciel/Sylius,Zales0123/Sylius,101medialab/Sylius,pjedrzejewski/Sylius,loic425/Sylius,SyliusBot/Sylius,pjedrzejewski/Sylius,mbabker/Sylius,antonioperic/Sylius,antonioperic/Sylius,lchrusciel/Sylius,mbabker/Sylius,Arminek/Sylius,pamil/Sylius,pamil/Sylius,Zales0123/Sylius,Sylius/Sylius,GSadee/Sylius,antonioperic/Sylius,Sylius/Sylius,Arminek/Sylius,diimpp/Sylius,Zales0123/Sylius,SyliusBot/Sylius,diimpp/Sylius,Arminek/Sylius,loic425/Sylius,GSadee/Sylius,lchrusciel/Sylius,101medialab/Sylius,diimpp/Sylius,pjedrzejewski/Sylius