Whereas the existing TestContextConcurrencyTests verify support for
concurrency in the TestContextManager and TestContext, this commit
introduces SpringJUnit4ConcurrencyTests that verify support for
concurrent test execution in Spring's JUnit 4 support, namely in the
SpringRunner, SpringClassRule, and SpringMethodRule.
The tests executed by this new test class come from a hand-picked
collection of test classes within the test suite that is intended to
cover most categories of tests that are currently supported by the
TestContext Framework on JUnit 4.
Note, however, that the chosen test classes intentionally do not
include any classes that fall under the following categories.
- tests that make use of Spring's @DirtiesContext support
- tests that make use of JUnit 4's @FixMethodOrder support
- tests that commit changes to the state of a shared in-memory database
Issue: SPR-5863