Update spec runner for full sass-spec coverage

[nschonni]

• Update the spec runner from work in sass-spec
• Bump sass-spec tag to 3.3.6

[nschonni]

OK, I've rebase the commits. I think it's ready for review/landing now

[xzyfer]

Nice one. I'm too fussed with specifics of the implementation as long as it works. If you're happy with it 🚢

[xzyfer]

Related #1705

[xzyfer]

Nice one. I had originally cherry-picked this PR into mine. I figured there was value in having them separate incase mine needed to be reverted. 🚢

[nschonni]

Yeah, I wanted to make sure they worked together

[nschonni]

Think I need to add back in the path replacements for Windows. I'll take a look tomorrow

[nschonni]

Think this should fix the wall of Windows errors, but I'm not getting this

  1) cli node-sass sass/ --output css/ should not error if output directory is a symlink:
     Error: EEXIST: file already exists, mkdir 'C:\Workspaces\node-sass\test\fixtures\input-directory\css'
      at Error (native)
      at Object.fs.mkdirSync (fs.js:794:18)
      at Context.<anonymous> (C:\Workspaces\node-sass\test\cli.js:582:10)
      at callFnAsync (C:\Workspaces\node-sass\node_modules\mocha\lib\runnable.js:349:8)
      at Test.Runnable.run (C:\Workspaces\node-sass\node_modules\mocha\lib\runnable.js:301:7)
      at Runner.runTest (C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:422:10)
      at C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:528:12
      at next (C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:342:14)
      at C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:352:7
      at next (C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:284:14)
      at Immediate._onImmediate (C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:320:5)

  2) cli node-sass --follow --output output-dir input-dir should compile with the --follow option:
     Error: EEXIST: file already exists, mkdir 'C:\Workspaces\node-sass\test\fixtures\follow\input-dir'
      at Error (native)
      at Object.fs.mkdirSync (fs.js:794:18)
      at Context.<anonymous> (C:\Workspaces\node-sass\test\cli.js:623:10)
      at callFnAsync (C:\Workspaces\node-sass\node_modules\mocha\lib\runnable.js:349:8)
      at Test.Runnable.run (C:\Workspaces\node-sass\node_modules\mocha\lib\runnable.js:301:7)
      at Runner.runTest (C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:422:10)
      at C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:528:12
      at next (C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:342:14)
      at C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:352:7
      at next (C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:284:14)
      at Immediate._onImmediate (C:\Workspaces\node-sass\node_modules\mocha\lib\runner.js:320:5)

But I may just have something broken somehow when I reset my branch. Appveyor will tell the truth

[xzyfer]

@nschonni I believe this is because our tests have side effects i.e. creating files on disk. Not all the tests clean up after themselves. So running tests after a failed run could end up with created files having not been removed.

We need to address this because it can cause issues with the retry added for the timeouts in CI.

[nschonni]

I'll see if I can find out what needs to change in the before/after test to see what might need cleaning up