Test: Add tests for the demo applications using TestContainers

[bsbodden]

We use a Redis fork of Test Containers () to do integration testing, with one base class for each type of persistence/repositories:

• https://github.com/redis/redis-om-spring/blob/main/redis-om-spring/src/test/java/com/redis/om/spring/AbstractBaseDocumentTest.java for @Document tests
• https://github.com/redis/redis-om-spring/blob/main/redis-om-spring/src/test/java/com/redis/om/spring/AbstractBaseEnhancedRedisTest.java for @RediHash tests

The tasks would be to write tests for the 3 demos applications under /demos to provide an example for users.

Possibly depends on #93

[maorohana-redis]

comment