Update rules_docker pin to new commit (#199)

* Update rules_docker pin to new commit

* Fix conflicting output digest issue

Pull in new version of base_images_docker that allows you to specify the
output digest name in the apt_key rule and use the new parameter to
avoid the conflict
diff --git a/repositories/repositories.bzl b/repositories/repositories.bzl
index 2248d42..e76a498 100644
--- a/repositories/repositories.bzl
+++ b/repositories/repositories.bzl
@@ -54,9 +54,9 @@
     if "io_bazel_rules_docker" not in excludes:
         http_archive(
             name = "io_bazel_rules_docker",
-            sha256 = "78083b4664b56b23ae1baccd69cb66de8f185a8b627c22ca415e0708cf0bf7b6",
-            strip_prefix = "rules_docker-0faaa7180810ad04d41e931488c7794c18c8d7a4",
-            urls = ["https://github.com/bazelbuild/rules_docker/archive/0faaa7180810ad04d41e931488c7794c18c8d7a4.tar.gz"],
+            sha256 = "d9ee70d2f763ce197e2691f12d69ee8e32b2245a48d53b4365fa239b66405c0c",
+            strip_prefix = "rules_docker-7391b39ccad788524262e106d54adfdbfc3e44d5",
+            urls = ["https://github.com/bazelbuild/rules_docker/archive/7391b39ccad788524262e106d54adfdbfc3e44d5.tar.gz"],
         )
 
     # io_bazel_rules_go is the dependency of container_test rules.
@@ -70,9 +70,9 @@
     if "base_images_docker" not in excludes:
         http_archive(
             name = "base_images_docker",
-            sha256 = "e2b1b7254270bb7605e814a9dbf6d1e4ae04a11136ff1714fbfdabe3f87f7cf9",
-            strip_prefix = "base-images-docker-12801524f867e657fbb5d1a74f31618aff181ac6",
-            urls = ["https://github.com/GoogleCloudPlatform/base-images-docker/archive/12801524f867e657fbb5d1a74f31618aff181ac6.tar.gz"],
+            sha256 = "c491e669299c842da1c1767c5bde73c3740b2fae19b9e38dae1732ca1725a2ef",
+            strip_prefix = "base-images-docker-635108c36ae89167a3ca8eb53706aed641145177",
+            urls = ["https://github.com/GoogleCloudPlatform/base-images-docker/archive/635108c36ae89167a3ca8eb53706aed641145177.tar.gz"],
         )
 
     if "distroless" not in excludes:
diff --git a/rules/container/debian_pkg_tar.bzl b/rules/container/debian_pkg_tar.bzl
index d76fb38..e4ca3d2 100644
--- a/rules/container/debian_pkg_tar.bzl
+++ b/rules/container/debian_pkg_tar.bzl
@@ -89,6 +89,7 @@
         image_with_keys_output_executable = ctx.actions.declare_file(image_with_keys)
         image_with_keys_output_tarball = ctx.actions.declare_file(image_with_keys + ".tar")
         image_with_keys_output_layer = ctx.actions.declare_file(image_with_keys + "-layer.tar")
+        image_with_keys_output_digest = ctx.actions.declare_file(image_with_keys + ".digest")
 
         _apt_key.implementation(
             ctx,
@@ -98,6 +99,7 @@
             output_executable = image_with_keys_output_executable,
             output_tarball = image_with_keys_output_tarball,
             output_layer = image_with_keys_output_layer,
+            output_digest = image_with_keys_output_digest,
         )
         download_base = image_with_keys_output_tarball