Update containerd to ec15fe95aa.

Signed-off-by: Lantao Liu <lantaol@google.com>

vendor.conf

@@ -1,7 +1,7 @@
 github.com/blang/semver v3.1.0
 github.com/BurntSushi/toml v0.2.0-21-g9906417
 github.com/containerd/cgroups 29da22c6171a4316169f9205ab6c49f59b5b852f
-github.com/containerd/containerd 12eaf13f6f12e5a4db52afe66876cf62fe7835cf
+github.com/containerd/containerd ec15fe95aa8fd3abeb05d036e1579129c0ba7b1c
 github.com/containerd/continuity cf279e6ac893682272b4479d4c67fd3abf878b4e
 github.com/containerd/fifo fbfb6a11ec671efbe94ad1c12c2e98773f19e1e6
 github.com/containerd/typeurl f6943554a7e7e88b3c14aad190bf05932da84788
@@ -32,10 +32,11 @@ github.com/gregjones/httpcache 787624de3eb7bd915c329cba748687a3b22666a6
 github.com/hashicorp/errwrap 7554cd9344cec97297fa6649b055a8c98c2a1e55
 github.com/hashicorp/go-multierror ed905158d87462226a13fe39ddf685ea65f1c11f
 github.com/inconshreveable/mousetrap 76626ae9c91c4f2a10f34cad8ce83ea42c93bb75
-github.com/json-iterator/go 13f86432b882000a51c6e610c620974462691a97
+github.com/json-iterator/go 1.0.4
 github.com/juju/ratelimit 5b9ff866471762aa2ab2dced63c9fb6f53921342
 github.com/mailru/easyjson d5b7844b561a7bc640052f1b935f7b800330d7e0
 github.com/Microsoft/go-winio v0.4.5
+github.com/Microsoft/hcsshim v0.6.7
 github.com/opencontainers/go-digest 21dfd564fd89c944783d00d069f33e3e7123c448
 github.com/opencontainers/image-spec v1.0.1
 github.com/opencontainers/runc 9f9c96235cc97674e935002fc3d78361b696a69e
@@ -53,7 +54,7 @@ github.com/sirupsen/logrus v1.0.0
 github.com/spf13/cobra v0.0.1
 github.com/spf13/pflag v1.0.0
 github.com/stretchr/testify v1.1.4
-github.com/syndtr/gocapability e7cb7fa329f456b3855136a2642b197bad7366ba
+github.com/syndtr/gocapability db04d3cc01c8b54962a58ec7e491717d06cfcc16
 github.com/tchap/go-patricia 5ad6cdb7538b0097d5598c7e57f0a24072adf7dc
 golang.org/x/net 7dcfb8076726a3fdd9353b6b8a1f1b6be6811bd6
 golang.org/x/sync 450f422ab23cf9881c94e2db30cac0eb1b7cf80c