e2e test setup. cc @hanahmily @peng-yongsheng @IanCao @zhaoyuguang @JaredTan95 

# e2e test case
One single standalone Spring service, accessing H2 database. This service has been installed the agent. 
OAP runs in single mode with H2 storage too.

The e2e test will verify the results through GraphQL query
1. Traces exist.
2. Service/Service Instance/Endpoint exist and have expected metrics.
3. Topology exists and match expected.

* Add login filter

Username and password are stored in application.yml with
prefix "security.user"

* Modify startup script and add webapp.yml config file

* Update quick-start document for default login username/password

* Update deploy document for new webapp.yml config file

* Update license for new files.

fix #931 

* Update docs for alpha release

* Delete a comma.

* Update How-to-build.md

* Add data-set licenses file

* Rename LICENSES-data-set to LICENSE-data-set

* Update LICENSE

* Remove fastclick from LICENSE

* Make the git submodule command to be a maven profile plugin. Let this command not execute by default install command.

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

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

* Product name is not correct

* Add more documents for release.

* Change profile id.

* Add CHANGES file in distribution file.

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

This reverts commit ac815019.

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

This reverts commit 095597c9.

* Add rat plugin to check dependency license and add license head into missing files.

* Fix docs.

* Exclude web ui config file.

* Next release guide.

* UI update.

* Update docs.

* Build source shell.