Cleanups of build including upgrade of Brave (#1530)

In efforts to dig deep into benchmarks, I noticed we were a bit out of
date on Brave. Then, noticed some other artifacts could be bumped
safely. Finally, a find/replace on http/https was over zealous and
tripped up XML.

One change to test expectations and Brave is explained here:
https://github.com/openzipkin/brave/blob/master/instrumentation/RATIONALE.md#calling-spanfinish-while-the-context-is-in-scope

spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-websocket/pom.xml

@@ -15,7 +15,7 @@
   ~ limitations under the License.
   -->
 
-<project xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 xmlns="http://maven.apache.org/POM/4.0.0"
 		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
@@ -57,7 +57,6 @@
 				</configuration>
 			</plugin>
 			<plugin>
-				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-compiler-plugin</artifactId>
 				<configuration>
 					<source>1.8</source>