Allow build on stable

[macisamuele]

The main goal of this PR is to ensure that the library could be used on stable release.

In order to achieve so I removed the explicit request for the proc_macro feature gate as it has been stabilised in rustc 1.29; the presence of such gate would cause cargo +stable build to fail.

To prevent regressions I made sure that:

• tests will be continuously run on stable and nightly releases
• documentation is tested (so we can guarantee that the provided examples are actually working)

[synek317]

Thank you very much! This is a huge step towards v. 1.0 which I was thinking about but had no time.

[macisamuele]

@synek317 do you have an estimation on when this PR could be merged?
I don't see opened issues and I would love to use a released version instead of continuing to rely on a personal git repo :)

[macisamuele]

Hey @synek317, sorry for pinging you again.
Do we have a timeline for this?
I would like to use the library for running tests on rust-stable and this PR would help

[macisamuele]

@synek317 do we have updates on this?
I would love to have this merged as this enables using the library while running tests with rust stable.

[frondeus]

Hello, sorry for no answer.

I agreed with Marcin that I'll take care of this project.
Right now you can use test-case = "0.3.0" which brings your changes.

However there are some breaking changes like replacing :: with ; in macro attribute.
Feel free to leave a comment there :)

@synek317 will soon deprecate this crate in favor of mine.

[macisamuele]

@frondeus good to know. I'll give a try to the new crate and open issues there in case of need.