travis.yml: fix umask for brew audit.
travis.yml: fix umask for brew audit.

Change the umask before we create any files to avoid `brew audit`
complaining about the `chmod` of formulae.

konqui/brew,ilovezfs/brew,claui/brew,Homebrew/brew,mahori/brew,konqui/brew,alyssais/brew,claui/brew,sjackman/homebrew,reitermarkus/brew,reelsense/brew,DomT4/brew,jmsundar/brew,maxim-belkin/brew,hanxue/linuxbrew,reitermarkus/brew,jmsundar/brew,aw1621107/brew,maxim-belkin/brew,alyssais/brew,EricFromCanada/brew,nandub/brew,DomT4/brew,Linuxbrew/brew,aw1621107/brew,amar-laksh/brew_sudo,nandub/brew,hanxue/linuxbrew,palxex/brew,sjackman/homebrew,palxex/brew,vitorgalvao/brew,mgrimes/brew,reelsense/brew,amar-laksh/brew_sudo,jmsundar/brew,DomT4/brew,sjackman/homebrew,aw1621107/brew,EricFromCanada/brew,ilovezfs/brew,JCount/brew,mahori/brew,claui/brew,reelsense/brew,claui/brew,vitorgalvao/brew,konqui/brew,Linuxbrew/brew,mahori/brew,Homebrew/brew,alyssais/brew,JCount/brew,reitermarkus/brew,vitorgalvao/brew,Linuxbrew/brew,pseudocody/brew,konqui/brew,JCount/brew,pseudocody/brew,amar-laksh/brew_sudo,reitermarkus/brew,MikeMcQuaid/brew,DomT4/brew,palxex/brew,mgrimes/brew,sjackman/homebrew,MikeMcQuaid/brew,vitorgalvao/brew,mahori/brew,nandub/brew,MikeMcQuaid/brew,ilovezfs/brew,Linuxbrew/brew,maxim-belkin/brew,mgrimes/brew,MikeMcQuaid/brew,Homebrew/brew,Homebrew/brew,hanxue/linuxbrew,pseudocody/brew,EricFromCanada/brew,JCount/brew,EricFromCanada/brew,nandub/brew