Add support for setting headers

[ainformatico]

Usefull for example when setting the User-Agent.

[jaimeiniesta]

Thank you @ainformatico -- I like the idea, but this needs specs for the new feature. I can merge this as soon as the specs are added and the broken specs are fixed.

[ainformatico]

sorry, I forgot the tests. I just patched what I needed.
I'll do it.

[ainformatico]

I hope is enough.

[jaimeiniesta]

Looks good, thanks!

Let me review this tomorrow before I merge it.

[ugran]

Is it already possible to pass user agent?

[jaimeiniesta]

No, this hasn't been merged yet, we're waiting for the specs. I can deal with them on the following days if there's no further activity.

[ainformatico]

Sorry, for some reason Github stopped sending me notifications emails until now.
I won't have time this week to work on this, if you can do it please go ahead.

I would recommend to set the default user agent to be like:

"MetaInspector/#{MetaInspector::VERSION} (+https://github.com/jaimeiniesta/metainspector)"

[jaimeiniesta]

@ainformatico I've merged your commits and added specs here a72aad4

I've released it as 2.2.0, can you try it to see if it works as expected?

Thanks!

[ainformatico]

works like a charm!

Thanks.