Merge pull request #1112 from ipfs/encapsulate_ipfs_mount

sharness: encapsulate ipfs mount

test/sharness/t0030-mount.sh

@@ -21,10 +21,11 @@ test_launch_ipfs_daemon
 #  test mount failure before mounting properly.
 
 test_expect_success "'ipfs mount' fails when there is no mount dir" '
-	test_must_fail ipfs mount -f=not_ipfs -n=not_ipns >output 2>output.err
+	tmp_ipfs_mount() { ipfs mount -f=not_ipfs -n=not_ipns >output 2>output.err; } &&
+	test_must_fail tmp_ipfs_mount
 '
 
-test_expect_failure "'ipfs mount' output looks good" '
+test_expect_success "'ipfs mount' output looks good" '
 	test_must_be_empty output &&
 	test_should_contain "not_ipns\|not_ipfs" output.err
 '