Move all remaining fixtures to `test/support/fixtures`.

Library/Homebrew/cask/spec/spec_helper.rb

Library/Homebrew/cask/test/test_helper.rb

...ures/bottles/testball_bottle-0.1.el_capitan.bottle.tar.gz

...es/bottles/testball_bottle-0.1.linux_x86_64.bottle.tar.gz

...bottles/testball_bottle-0.1.macintosh_intel.bottle.tar.gz

...tures/bottles/testball_bottle-0.1.mavericks.bottle.tar.gz

...s/bottles/testball_bottle-0.1.mountain_lion.bottle.tar.gz

...fixtures/bottles/testball_bottle-0.1.sierra.bottle.tar.gz

...xtures/bottles/testball_bottle-0.1.yosemite.bottle.tar.gz

...ary/Homebrew/test/support/fixtures/cask/AppWithBinary.zip

...brew/test/support/fixtures/cask/AppWithEmbeddedBinary.zip

Library/Homebrew/test/support/fixtures/cask/MyFancyApp.zip

Library/Homebrew/test/support/fixtures/cask/MyFancyPkg.zip

...ary/Homebrew/test/support/fixtures/cask/NestedApp.dmg.zip

...ry/Homebrew/test/support/fixtures/cask/caffeine-suite.zip

Library/Homebrew/test/support/fixtures/cask/caffeine.zip

.../Homebrew/test/support/fixtures/cask/caffeines-subdir.zip

Library/Homebrew/test/support/fixtures/cask/caffeines.zip

Library/Homebrew/test/support/fixtures/cask/container.7z

Library/Homebrew/test/support/fixtures/cask/container.air