Stop publishing the test directory

[fvictorio]

The files array in the package.json includes the test directory, but this is not necessary according to @pfmescher's research (see this comment).

It's very likely that just removing the directory from files is enough, but we should validate that this doesn't break anything. The easiest way to do that is to remove the directory from files, then use npm pack to create a package, and then install the created .tgz in a real project and verify that it works.

[dbale-altoros]

Removing the files keyword in the package.json is no good
I made an npm pack without the file keyword in the package.json and installed such pack in a fresh project...
The test folder is no longer in the package, but when I try to make solhint --init I get MODULE NOT FOUND for each rule having a /test/fixture/.... something.js
Seems we need to split test from documentation or leave it as it is

@pfmescher @fvictorio

[fvictorio]

I see. Yes, we should probably move all those fixtures to an examples directory outside the test directory, and include that in files instead of test. Low priority though.

[dbale-altoros]

agree

[dbale-altoros]

#730