* Moves to Maven wrapper to stabilize the version in use

This will ensure those building will have similar experience due to
having a fixed maven version.

* Updates most plugin versions and removes redundant configuration

* Sets up build enforcement for JDK 1.8 until further work occurs

* Change version 

* [maven-release-plugin] prepare release apm-5.0.0-alpha

* [maven-release-plugin] prepare for next development iteration

Fix assmbly for mvn clean install -Papache-release and update version to SNAPSHOT for SNAPSHOT release.

Add “checkStyle.xml” and “codeStyle.xml” files, varify the code-style when “mvn compile” and CI. This is the initialized commit.

2.Release the prototype of ‘TraceSegment’.