Replace bash test with [[ ]].

Partial mas-cli#638

Signed-off-by: Ross Goldberg <484615+rgoldberg@users.noreply.github.com>

script/bottle

@@ -114,7 +114,7 @@ brew install --build-bottle mas-cli/tap/mas
 
 # Generate bottle do block, dropping last 2 lines
 brew bottle --verbose --no-rebuild --root-url="${ROOT_URL}" mas-cli/tap/mas
-if ! test -e "${OLD_FILENAME}"; then
+if [[ ! -e "${OLD_FILENAME}" ]]; then
   echo "Bottle not found: ${OLD_FILENAME}"
   echo "If an old version is showing in the log and filename, then make sure the formula has been updated in:"
   echo "${CORE_TAP_PATH}"

script/install

@@ -15,7 +15,7 @@ RELEASE=".build/${ARCH}-apple-macosx/release"
 MAS_VERSION="$(script/version)"
 PREFIX=/usr/local
 
-while test -n "${1}"; do
+while [[ -n "${1}" ]]; do
   if [[ "${1}" == '--universal' ]]; then
     ARCH=universal
     RELEASE=.build/release