[Security] Bump nokogiri from 1.8.2 to 1.8.4

[dependabot-preview]

Bumps nokogiri from 1.8.2 to 1.8.4. This update includes security fixes.

Vulnerabilities fixed

Sourced from The Ruby Advisory Database.

Revert libxml2 behavior in Nokogiri gem that could cause XSS
[MRI] Behavior in libxml2 has been reverted which caused
CVE-2018-8048 (loofah gem), CVE-2018-3740 (sanitize gem), and
CVE-2018-3741 (rails-html-sanitizer gem). The commit in question is
here:

GNOME/libxml2@960f0e2

and more information is available about this commit and its impact
here:

... (truncated)

Patched versions: >= 1.8.3
Unaffected versions: none

Changelog

Sourced from nokogiri's changelog.

1.8.4 / 2018-07-03

Bug fixes

• [MRI] Fix memory leak when creating nodes with namespaces. (Introduced in v1.5.7) [Bump progress_bar from 1.2.0 to 1.3.0 #1771]

1.8.3 / 2018-06-16

Security Notes

[MRI] Behavior in libxml2 has been reverted which caused CVE-2018-8048 (loofah gem), CVE-2018-3740 (sanitize gem), and CVE-2018-3741 (rails-html-sanitizer gem). The commit in question is here:

GNOME/libxml2@960f0e2

and more information is available about this commit and its impact here:

https://github-redirect.dependabot.com/flavorjones/loofah/issues/144

This release simply reverts the libxml2 commit in question to protect users of Nokogiri's vendored libraries from similar vulnerabilities.

If you're offended by what happened here, I'd kindly ask that you comment on the upstream bug report here:

https://bugzilla.gnome.org/show_bug.cgi?id=769760

Dependencies

• [MRI] libxml2 is updated from 2.9.7 to 2.9.8

Features

• Node#classes, #add_class, #append_class, and #remove_class are added.
• NodeSet#append_class is added.
• NodeSet#remove_attribute is a new alias for NodeSet#remove_attr.
• NodeSet#each now returns an Enumerator when no block is passed (Thanks, park53kr!)
• [JRuby] General improvements in JRuby implementation (Thanks, kares!)

Bug fixes

• CSS attribute selectors now gracefully handle queries using integers. [Jw delete services email fix #711]
• Handle ASCII-8BIT encoding on fragment input [SAW - do not display in sparc (fixes) (1.7.5) #553]
• Handle non-string return values within Reader [Ssr deletion bug [#139232829] #898]
• [JRuby] Allow Node#replace to insert Comment and CDATA nodes. [KG - Disable eIRB Fields on Edit if eIRB Validated #1666]
• [JRuby] Stability and speed improvements to Node, Sax::PushParser, and the JRuby implementation [Sparc request branding - Replacing 'SPARC Request' with 'SPARCRequest' #1708, #1710, #1501]

Commits

• 254f341 version bump to v1.8.4
• 056f66d enforcing formatting in xml_node.c
• ca4f9b2 Merge branch '1771-memory-leak'
• 0d26561 fix memory leak with creating nodes with a namespace
• 117ca2e README format
• 20e11c3 version bump to 1.8.3
• be8a240 update CHANGELOG
• 06ac6ba Merge branch '1765-enumerator'
• 00bafb7 add test coverage for NodeSet#each enum
• 75517e0 '#each' returns enumerator when no block given
• Additional commits viewable in compare view

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