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/pause_options.go

@@ -11,7 +11,6 @@ package hcsschema
 
 //  Options for HcsPauseComputeSystem
 type PauseOptions struct {
-
 	SuspensionLevel string `json:"SuspensionLevel,omitempty"`
 
 	HostedNotification *PauseNotification `json:"HostedNotification,omitempty"`