code: function createRule(selector, declarations, node) {
  		let rule = postcss.rule({
  			selector: selector,
  			source: node.source
  		});
  
  		declarations.forEach(decl => {
  			rule.append(createDeclaration(decl.prop, decl.value, node));
  		});
  
  		return rule;
  	}
docs: Create postcss declaration with meta info from mixin
  
  @param {string} selector
  @param {Array} declarations - one or many postcss.Declaration
  @param {object} node - postcss.Mixin
  @returns {Rule}