style: fix lint report

Author: Scrum

lib/index.js

@@ -156,7 +156,7 @@ function traverse (tree, cb) {
 function isSingleTag (tag, singleTags, singleRegExp) {
   if (singleRegExp.length) {
     for (var i = 0; i < singleRegExp.length; i++) {
-      return tag.match(singleRegExp[i]) ? true : false
+      return !!tag.match(singleRegExp[i])
     }
   }
 

test/render.test.js

@@ -222,14 +222,14 @@ describe('PostHTML Render', function () {
         expect(render(fixture, options)).to.eql(expected)
       })
 
-      it('Custom {RegExp}', function() {
+      it('Custom {RegExp}', function () {
         var options = { singleTags: [ /^%.*%$/ ] }
 
         var fixture = { tag: '%=title%' }
         var expected = '<%=title%>'
 
         expect(render(fixture, options)).to.eql(expected)
-      });
+      })
 
       it('Attrs', function () {
         var options = { singleTags: [ 'rect' ] }