Update RoaringBitmap to 0.4.3

Roaring has been updated to version 0.4.3. We fixed a rarely occurring bug with serialization. No API or format changes were made.

Author: Daniel Lemire <lemire@gmail.com>

Closes #2938 from lemire/master and squashes the following commits:

431f3a0 [Daniel Lemire] Recommended bug fix release
[SPARK-3616] Add basic Selenium tests to WebUISuite

This patch adds Selenium tests for Spark's web UI.  To avoid adding extra
dependencies to the test environment, the tests use Selenium's HtmlUnitDriver,
which is pure-Java, instead of, say, ChromeDriver.

I added new tests to try to reproduce a few UI bugs reported on JIRA, namely
SPARK-3021, SPARK-2105, and SPARK-2527.  I wasn't able to reproduce these bugs;
I suspect that the older ones might have been fixed by other patches.

In order to use HtmlUnitDriver, I added an explicit dependency on the
org.apache.httpcomponents version of httpclient in order to prevent jets3t's
older version from taking precedence on the classpath.

I also upgraded ScalaTest to 2.2.1.

Author: Josh Rosen <joshrosen@apache.org>
Author: Josh Rosen <joshrosen@databricks.com>

Closes #2474 from JoshRosen/webui-selenium-tests and squashes the following commits:

fcc9e83 [Josh Rosen] scalautils -> scalactic package rename
510e54a [Josh Rosen] [SPARK-3616] Add basic Selenium tests to WebUISuite.
Just fixing comment that shows usage

Author: anant asthana <anant.asty@gmail.com>

Closes #2948 from anantasty/patch-1 and squashes the following commits:

d8fea0b [anant asthana] Just fixing comment that shows usage
[SPARK-3925][SQL] Do not consider the ordering of qualifiers during comparison

The orderings should not be considered during the comparison between old qualifiers and new qualifiers.

Author: Liang-Chi Hsieh <viirya@gmail.com>

Closes #2783 from viirya/full_qualifier_comp and squashes the following commits:

89f652c [Liang-Chi Hsieh] modification for comment.
abb5762 [Liang-Chi Hsieh] More comprehensive comparison of qualifiers.
[HOTFIX][SQL] Temporarily turn off hive-server tests.

The thirift server is not available in the default (hive13) profile yet which is breaking all SQL only PRs.  This turns off these test until #2685 is merged.

Author: Michael Armbrust <michael@databricks.com>

Closes #2950 from marmbrus/fixTests and squashes the following commits:

1a6dfee [Michael Armbrust] [HOTFIX][SQL] Temporarily turn of hive-server tests.