Add a couple of tests for "run"

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

tests/run.bats

@@ -0,0 +1,26 @@
+#!/usr/bin/env bats
+
+load helpers
+
+@test "run" {
+	if ! which runc ; then
+		skip
+	fi
+	createrandom ${TESTDIR}/randomfile
+	cid=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json --image alpine)
+	root=$(buildah mount --name=$cid)
+	buildah config --name=$cid --workingdir /tmp
+	run buildah --debug=false run --name=$cid pwd
+	output=$(echo "$output" | tr -d '\r')
+	[ "$output" = /tmp ]
+	buildah config --name=$cid --workingdir /root
+	run buildah --debug=false run        $cid pwd
+	output=$(echo "$output" | tr -d '\r')
+	[ "$output" = /root ]
+	cp ${TESTDIR}/randomfile $root/tmp/
+	buildah run        $cid cp /tmp/randomfile /tmp/other-randomfile
+	test -s $root/tmp/other-randomfile
+	cmp ${TESTDIR}/randomfile $root/tmp/other-randomfile
+	buildah unmount --name=$cid
+	buildah delete --name=$cid
+}