Upgraded bazel-starlib and added custom workspace name to workspace snippet generation.

[cgrindel]

Related to cgrindel/bazel-starlib#106.

• Upgraded bazel-starlib to v0.5.0.
• Added custom workspace name to //release:generate_workspace_snippet target.

Workspace snippet for v999.0.0

# Generate workspace snippet for tag v999.0.0
bazel run //release:generate_workspace_snippet -- --tag v999.0.0

Output:

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
    name = "buildifier_prebuilt",
    sha256 = "f24270b5e8fe2b1663848c74c452c54609640bfd200f9a5befb6850b8d778a6a",
    strip_prefix = "buildifier-prebuilt-999.0.0",
    urls = [
        "http://github.com/cgrindel/buildifier-prebuilt/archive/v999.0.0.tar.gz",
    ],
)

load("@buildifier_prebuilt//:deps.bzl", "buildifier_prebuilt_deps")

buildifier_prebuilt_deps()

load("@bazel_skylib//:workspace.bzl", "bazel_skylib_workspace")

bazel_skylib_workspace()

load("@buildifier_prebuilt//:defs.bzl", "buildifier_prebuilt_register_toolchains")

buildifier_prebuilt_register_toolchains()