Build and tag a release

[squeed]

Now that this is a Real Repository, it's time to tag a version (maybe v0.5? v1.0?) and build a package.

If you want some inspiration, you can use the cni-plugins release script, though it's not perfect.

[electrocucaracha]

Solving this issue can help on closing this other containernetworking/plugins#655

[dghubble]

The flannel plugin included in the last release of https://github.com/containernetworking/plugins/releases/tag/v0.9.1 before flannel was removed.

flannel: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, Go BuildID=dZDcTERtH-9PDJCdAkON/0VMQloxmtbI4Rs2kxaLM/5AymBM7OvwcRuvlCMu2q/JsjTHehliJowKeV_7xDZ, not stripped

The flannel-amd64 plugin released here is dynamically linked @rajatchopra

flannel-amd64: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, Go BuildID=9Cq5UwPMeAEU_rzzswhc/Dpkfak7tfSJG3o3RSxyQ/2axg57cG
cG_xgl_gk1Mp/Q8_6RsogHe8oG0i6TkI1, not stripped

[manuelbuil]

I think we finally have a release pipeline :)

[luthermonson]

this should all be wrapped up and done with #22 and it's subsequent patches. im going to close this as we believe we're done.