fix(tests): refactor tests and junit platform name to execute startup tests

[j-sandy]

Startup test under module keiko-mem-spring and keiko-redis-spring are not executing and throwing below error:

> Task :keiko-mem-spring:test FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':keiko-mem-spring:test'.
> No tests found for given includes: [com.netflix.spinnaker.q.mem.spring.SpringStartupTests](--tests filter)

> Task :keiko-redis-spring:test FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':keiko-redis-spring:test'.
> No tests found for given includes: [com.netflix.spinnaker.q.redis.spring.SpringStartupTests](--tests filter)

After fixing these issues by refactoring the junit platform as junit-jupiter, encountered below errors while execution:

Failed to load ApplicationContext
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.netflix.spectator.api.Registry' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}
	at app//org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1801)
	at app//org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1357)
	at app//org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1311)
	at app//org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:911)
	at app//org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:788)
	... 133 more

Failed to load ApplicationContext
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.netflix.spinnaker.q.redis.RedisQueue]: Factory method 'queue' threw exception; nested exception is redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
	at app//org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
	at app//org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:648)
	... 120 more

To fix these errors refactored the test by adding Registry and JedisPool beans.