feat: allow rows with 100% statement, branch, and function coverage to be skipped in text report

[bcoe]

@chrismohr ☝️ I note that for skipEmpty we actually support both text and HTML reports; might be a good next contribution for you?

CC: @coreyfarrell for review.

[coreyfarrell]

@bcoe would be nice to add a test verifying that --skip-full doesn't skip sources that aren't fully covered. Otherwise this looks good to me.

    it('does displays files without 100% statement, branch, and function coverage', (done) => {
      const args = [
        bin,
        '--skip-full',
        process.execPath, './instrumented/s1.min.js'
      ]

      const proc = spawn(process.execPath, args, {
        cwd: fixturesSourceMaps,
        env: env
      })

      var stdout = ''
      proc.stdout.on('data', function (chunk) {
        stdout += chunk
      })

      proc.on('close', function (code) {
        code.should.equal(0)
        stdoutShouldEqual(stdout, `
        ----------|----------|----------|----------|----------|-------------------|
        File      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
        ----------|----------|----------|----------|----------|-------------------|
        All files |       80 |      100 |       50 |       80 |                   |
         s1.js    |       80 |      100 |       50 |       80 |                 7 |
        ----------|----------|----------|----------|----------|-------------------|`)
        done()
      })
    })