pkg_deb supports license attribute

[nstng]

This change adds an optional attribute to pkg_deb called license for providing a short license description of the packaged code to the artifact meta info. E.g.,

pkg_deb(
  ...
  license = "BSD-3-Clause",
  ...
)

$ dpkg -I foo.deb
...
 License: BSD-3-Clause
...

Closes #650.

Signed-off-by: Nils Semmelrock [email protected]

[google-cla]

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[nstng]

First PR here :) I did not find special contributor guidelines (apart from the CLA - which is in progress). Let me know if I missed something.
Unsure about adding this change to the docs - I only see 0.8.0 docs, but no upcoming/0.9.0 docs where I could add this.

[aiuto]

CLA https://cla.developers.google.com/

Don't worry about the docs. I do those periodically. But, if you want to try it, do what is in doc_build/BUILD

bazel build //doc_build:reference
cp bazel-bin/doc_build/reference.md docs/latest.md
git commit -m 'update docs' docs/latest.md

[nstng]

CLA https://cla.developers.google.com/

In progress - I need to do this via corporate (I don't expect issues, I just have to wait for approval)

Don't worry about the docs. I do those periodically. But, if you want to try it, do what is in doc_build/BUILD

bazel build //doc_build:reference
cp bazel-bin/doc_build/reference.md docs/latest.md
git commit -m 'update docs' docs/latest.md

added second commit with generated docs

[aiuto]

Great. I'll wait for the CLA. Ping this PR when you are ready and I can merge.

[nstng]

Hi @aiuto, got my CLA finally setup :)
PR is rebased and ready-for-review. (sry for the multiple rebases - had to change my author email)