Bump github.com/containers/storage from 1.15.1 to 1.15.2

Bumps [github.com/containers/storage](https://github.com/containers/storage) from 1.15.1 to 1.15.2.
- [Release notes](https://github.com/containers/storage/releases)
- [Changelog](https://github.com/containers/storage/blob/master/docs/containers-storage-changes.md)
- [Commits](https://github.com/containers/storage/compare/v1.15.1...v1.15.2)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

vendor/github.com/containers/storage/go.mod

@@ -3,11 +3,11 @@ module github.com/containers/storage
 require (
 	github.com/BurntSushi/toml v0.3.1
 	github.com/DataDog/zstd v1.4.0 // indirect
-	github.com/Microsoft/go-winio v0.4.14
-	github.com/Microsoft/hcsshim v0.8.6
+	github.com/Microsoft/go-winio v0.4.15-0.20190919025122-fc70bd9a86b5
+	github.com/Microsoft/hcsshim v0.8.7
 	github.com/docker/docker v0.0.0-20171019062838-86f080cff091 // indirect
 	github.com/docker/go-units v0.4.0
-	github.com/klauspost/compress v1.9.3
+	github.com/klauspost/compress v1.9.4
 	github.com/klauspost/cpuid v1.2.1 // indirect
 	github.com/klauspost/pgzip v1.2.1
 	github.com/mattn/go-shellwords v1.0.6
@@ -18,13 +18,14 @@ require (
 	github.com/pkg/errors v0.8.1
 	github.com/pquerna/ffjson v0.0.0-20181028064349-e517b90714f7
 	github.com/sirupsen/logrus v1.4.2
+	github.com/spf13/pflag v1.0.3 // indirect
 	github.com/stretchr/testify v1.4.0
 	github.com/syndtr/gocapability v0.0.0-20180916011248-d98352740cb2
 	github.com/tchap/go-patricia v2.3.0+incompatible
 	github.com/vbatts/tar-split v0.11.1
 	golang.org/x/net v0.0.0-20190628185345-da137c7871d7
-	golang.org/x/sys v0.0.0-20191127021746-63cb32ae39b2
-	gotest.tools v0.0.0-20190624233834-05ebafbffc79
+	golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3
+	gotest.tools v2.2.0+incompatible
 )
 
 go 1.13