The reporter should not output empty reports on console

[abhishekdev]

For the most basic setup (using built-in report formatters) the reporter outputs an empty line on console even if the report if effectively empty. This creates unwanted breaks in the console logs.

Example

For a gulpfile like:

var gulp = require('gulp');
var csslint = require('gulp-csslint');

gulp.task('default', ['lint:css']);

gulp.task('lint:css', function() {
  return gulp.src('src/**/*.css')
    .pipe(csslint())
    .pipe(csslint.reporter());
});

For a successful lint, output is:

[19:35:08] Using gulpfile ~/playzone/sampleproject/gulpfile.js
[19:35:08] Starting 'lint:css'...
[19:35:08] 
[19:35:08] Finished 'lint:css' after 38 ms
[19:35:08] Starting 'default'...
[19:35:08] Finished 'default' after 26 μs

• For text, compact report formats an empty line is printed for no errors/warnings. (ISSUE?)
• For *xml based report formats the root tags render, which is as per the XML syntax.

To be consistent with other linter outputs gulp-csslint should probably not print anything to console if the effective output of the report is empty.