Revendor github.com/Microsoft/hcsshim

1. Revendors github.com/Microsoft/hcsshim to the latest known good commit.
This includes numerous bug fixes and improvements.

2. Vendors indirect dependency on go.opencensus.io since hcsshim now uses trace
correlation.

Signed-off-by: Justin Terry (VM) <juterry@microsoft.com>

vendor/github.com/Microsoft/hcsshim/internal/schema2/memory.go

@@ -10,6 +10,5 @@
 package hcsschema
 
 type Memory struct {
-
 	SizeInMB int32 `json:"SizeInMB,omitempty"`
 }