Fix failing tests in nokogiri update

I've whittled the failing tests down to two:

```
  1) Failure:
test_non_inline_erb(ErbTest) [/Users/stefan/Projects/html2haml/test/erb_test.rb:31]:
--- expected
+++ actual
@@ -1,2 +1 @@
-"%p
-  = foo"
+"%p= foo"


  2) Failure:
test_script_tag_with_html_escaped_javascript(Html2HamlTest) [/Users/stefan/Projects/html2haml/test/html2haml_test.rb:154]:
--- expected
+++ actual
@@ -1,4 +1,4 @@
 ":javascript
   function foo() {
-      return \"12\" & \"13\";
+      return \"12\" &amp; \"13\";
   }"
```

Failure 2 seems like a really strange test case and I wanted to ask you what the motivation for it was. Is it a bad test?

And I am stuck trying to figure out Failure 1. If you have any insight, let me know.