Add sanity check option during/post installation to validate installation.

[gdennie]

A command to perform a validation of the installation by, perhaps, compiling an "hello, world!" program is necessary.

Presently, my install exited with a Failure 1 and so I have installed the zlib packages as recommended. I have elected to re-run the installation command, cabal install idris, without being certain doing so is necessary or advisable. Following all that I now have to find a usage scenario and some code to perform a compile in order to validate stuff just to complete the initial install.

[jfdm]

@gdennie Thanks for the suggestion.

I think having some form of sanity check post installation would be a good addition to the installation process.

We already have command line flags such as idris --info that helps with diagnosing ones installation, and the package tooling allows one to run tests which involve creation, compilation, and execution of an Idris program.

I know when installing through cabal a man page is installed into cabal's local man page location IIRC.

I think this (a sanity check option) would be a good example of a entry project for someone looking to get involved with Idris development.

[jfdm]

I'll also change the issue title to be more reflective of what the issue is.