openlmis-auth

This reverts commit d7de12a691485f3412f0342932693ed406151186.

To avoid errors during pipeline because directories cannot be deleted during git checkout.

To avoid errors in subsequent builds.

Using Boot version 2.2.2, as it is relatively recent.

* Flyway is at 6.0.8, new mechanism for loading Spring Security for OAuth2, and new versions for REST Assured, RAML tester, RAML parser, PowerMock (so tests will pass).

* Spring application properties for Flyway has changed.

* Fix repository method signatures (findOne is now findById, etc.); additionally they return Optional.

* Spring Security 5 has changed encoding of password storage to DelegatingPasswordEncoder. To be backwards-compatible, currently returning NoOpPasswordEncoder as default. Will probably need to migrate all passwords to new encoding and use a better encoder/decoder.

* Fix unit tests.

* Flyway is now at v6, and Java callback mechanism has changed to a general handle() method.

* Fix integration tests (including simplifying TokenIntegrationTest).

* Integration tests allow bean definition overriding, as it is not enabled by default now in Spring Boot 2.x.

* API definitions require "Keep-Alive" header for web integration tests.

The service token endpoint takes 10ms to execute on average. The test is currently invoking the endpoint over 1000 times per second. This may be overkill and not proportional to our testing needs.