Pass in context to lease done function in client

Allows the client to choose the context to finish the lease.
This allows the client to switch contexts when the main context
used to the create the lease may have been cancelled.

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

content_test.go

@@ -41,7 +41,7 @@ func newContentStore(ctx context.Context, root string) (context.Context, content
 		name  = testsuite.Name(ctx)
 	)
 
-	wrap := func(ctx context.Context) (context.Context, func() error, error) {
+	wrap := func(ctx context.Context) (context.Context, func(context.Context) error, error) {
 		n := atomic.AddUint64(&count, 1)
 		ctx = namespaces.WithNamespace(ctx, fmt.Sprintf("%s-n%d", name, n))
 		return client.WithLease(ctx)