Log Message:
Update ruby-jekyll-sass-converter to 1.4.0.

1.4.0 / 2015-12-25

Minor Enhancements

    Bump Sass to v3.4 and above. (#40)
    Strip byte order mark from generated compressed Sass/SCSS (#39)
    Strip BOM by default, but don't add in the @charset by default (#42)

Development Fixes

    Add Jekyll 2 & 3 to test matrix (#41)