package/ci: don't call brew update to speed up Travis build.
package/ci: don't call brew update to speed up Travis build.

mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,mosra/magnum-examples,Squareys/magnum-examples,mosra/magnum-examples,Squareys/magnum-examples,mosra/magnum-examples,Squareys/magnum-examples,Squareys/magnum-examples