Switch to new vendor directory layout

Fixes #113

Signed-off-by: Marcos Lilljedahl <marcosnils@gmail.com>

vendor/github.com/opencontainers/runc/libcontainer/stacktrace/frame_test.go

@@ -0,0 +1,20 @@
+package stacktrace
+
+import "testing"
+
+func TestParsePackageName(t *testing.T) {
+	var (
+		name             = "github.com/opencontainers/runc/libcontainer/stacktrace.captureFunc"
+		expectedPackage  = "github.com/opencontainers/runc/libcontainer/stacktrace"
+		expectedFunction = "captureFunc"
+	)
+
+	pack, funcName := parseFunctionName(name)
+	if pack != expectedPackage {
+		t.Fatalf("expected package %q but received %q", expectedPackage, pack)
+	}
+
+	if funcName != expectedFunction {
+		t.Fatalf("expected function %q but received %q", expectedFunction, funcName)
+	}
+}