Base 2.5.0 Released!

• Major updates on variable names for tablet, desktop and hd containers + breakpoints (_variables.less/_variables.scss)
• Major updates on column names, push and pull classes for tablet, desktop + hd (_grid.less/_grid.scss)
• Moved helpers from _grid.less/_grid.scss to _helpers.less/_helpers.scss
• Deleted _minimial-grid.less/_minimial-grid.scss
• Updated _helpers file with new tablet, desktop and hd helpers (fixes bug #51)
• Version bump on package.json
• Version bump on style.less/style.scss