test: add test for simpleLineBreak and pre tags

test/features/simpleLineBreaks-handle-html-pre.html

@@ -0,0 +1,4 @@
+<p>hmm</p>
+<pre>
+this is `a\_test` and this\_too and finally_this_is
+</pre>

test/features/simpleLineBreaks-handle-html-pre.md

@@ -0,0 +1,4 @@
+hmm
+<pre>
+this is `a\_test` and this\_too and finally_this_is
+</pre>

test/issues/handle-html-pre.html

@@ -0,0 +1,4 @@
+<p>hmm</p>
+<pre>
+this is `a\_test` and this\_too and finally_this_is
+</pre>

test/issues/handle-html-pre.md

@@ -0,0 +1,4 @@
+hmm
+<pre>
+this is `a\_test` and this\_too and finally_this_is
+</pre>

test/node/testsuite.features.js

@@ -45,6 +45,8 @@ describe('makeHtml() features testsuite', function () {
       converter = new showdown.Converter({simpleLineBreaks: true});
     } else if (testsuite[i].name === '#318.simpleLineBreaks-does-not-work-with-chinese-characters') {
       converter = new showdown.Converter({simpleLineBreaks: true});
+    } else if (testsuite[i].name === 'simpleLineBreaks-handle-html-pre') {
+      converter = new showdown.Converter({simpleLineBreaks: true});
     } else if (testsuite[i].name === 'excludeTrailingPunctuationFromURLs-option') {
       converter = new showdown.Converter({simplifiedAutoLink: true, excludeTrailingPunctuationFromURLs: true});
     } else if (testsuite[i].name === 'requireSpaceBeforeHeadingText') {