add a pass credential helper backend

Signed-off-by: Tycho Andersen <tycho@docker.com>

ci/before_script_linux.sh

@@ -2,3 +2,21 @@ set -ex
 
 sh -e /etc/init.d/xvfb start
 sleep 3 # give xvfb some time to start
+
+# init key for pass
+gpg --batch --gen-key <<-EOF
+%echo Generating a standard key
+Key-Type: DSA
+Key-Length: 1024
+Subkey-Type: ELG-E
+Subkey-Length: 1024
+Name-Real: Meshuggah Rocks
+Name-Email: meshuggah@example.com
+Expire-Date: 0
+# Do a commit here, so that we can later print "done" :-)
+%commit
+%echo done
+EOF
+
+key=$(gpg --no-auto-check-trustdb --list-secret-keys | grep ^sec | cut -d/ -f2 | cut -d" " -f1)
+pass init $key