travis-build.sh: do not update Homebrew

ctrueden · ctrueden · commit 89c9d928a1bc · 2018-11-16T16:11:02.000-06:00
It is very slow, and all we need is a working gnupg2.
diff --git a/travis-build.sh b/travis-build.sh
@@ -91,7 +91,7 @@ EOL
 	# Install GPG on OSX/macOS
 	if [ "$TRAVIS_OS_NAME" = osx ]
 	then
-		brew install gnupg2
+		HOMEBREW_NO_AUTO_UPDATE=1 brew install gnupg2
 	fi
 
 	# Import the GPG signing key.
