Default to annotated tags rather than lightweight

[patcon]

I haven't been in the habit of doing this myself, but just learned that annotated tags are the best-practice:
http://git-scm.com/book/en/Git-Basics-Tagging#Creating-Tags

Worth switching the default for? Would seem that lightweight tags would be a good override

[patcon]

If you'd like I can removed the signed case and could move that over to #65

If that is satisfactory for you, then I can work on documenting this. Just want confirmation before I do that bit of work :) Thanks!

[patcon]

Meh. Moved the signing stuff into other PR

[patcon]

Hm. Got this when didn't have a tagType in the config:

➜  roobot git:(master) grunt release
Running "release" task
>> bumped version to 0.0.2
>> staged package.json
>> committed package.json
Warning: Unrecognized tagType: "undefined". Use --force to continue.

[patcon]

Just noticed your commit @AsaAyers. Thanks for subsidizing my apparent laziness :)

I think this is ready to merge @geddski

[AsaAyers]

@geddski does anything else need to be done here?

[geddski]

my understanding was that we're already using annotated tags. git docs says:

If -m or -F is given and -a, -s, and -u are absent, -a is implied.

[patcon]

Ah so we are. I guess I'll convert this into working for just signed commits and annotated tags. Thanks @geddski

[drublic]

@patcon Thanks for your work. Is there anything to do here? Otherwise we could close this PR and work on #65 to get signed commits.

[patcon]

As I remember, this was a non-issue since the default was already annotated...? I think we're good to close.

[drublic]

Thanks for the update.