Add shippable tests. (#4)

tests/utils/shippable/linux.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+set -o pipefail -eux
+
+declare -a args
+IFS='/:' read -ra args <<< "$1"
+
+image="${args[1]}"
+
+if [ "${#args[@]}" -gt 2 ]; then
+    target="shippable/posix/group${args[2]}/"
+else
+    target="shippable/posix/"
+fi
+
+# shellcheck disable=SC2086
+ansible-test integration --color -v --retry-on-error "${target}" ${COVERAGE:+"$COVERAGE"} ${CHANGED:+"$CHANGED"} ${UNSTABLE:+"$UNSTABLE"} \
+    --docker "${image}"