Refactor internal tests to no longer use @SpringApplicationConfiguration

See gh-5562

This change was missed as part of the work done in 19d8c5e6.

See gh-5306
Closes gh-5543

This commit introduces a new annotation, @AutoConfigureRestDocs,
which can be used to enable auto-configuration of Spring REST Docs.
The auto-configuration removes the need to use Spring REST Docs' JUnit
rule and will automatically configure MockMvc. Combined with the new
auto-configuration for MockMvc it allows a test class to be free of
boilerplate configuration:

@RunWith(SpringRunner.class)
@WebMvcTest
@AutoConfigureRestDocs(outputDir = "target/generated-snippets",
        uriScheme = "https", uriHost = "api.example.com",
        uriPort = 443)
public class ExampleDocumentationTests {

    @Autowired
    private MockMvc mvc;

    @Test
    public void documentIndex() {
        // …
    }

}

For more advanced customization a RestDocsMockMvcConfigurationCustomizer
bean can be used.

If a RestDocumentationResultHandler is found in the context, it will
be passed to the ConfigurableMockMvcBuilder's alwaysDo method as part
of its customization.

Closes gh-5563

Closes gh-5556

In particular it now accepts a list of maps containing
"authority" keys (which is what you get from a standard JSON
decoding of a Spring Security Authentication).

Fixes gh-5482

In the web starter we shouldn't depend explicitly on any EL
implementation, otherwise when people build wars and deploy
them in containers that have their own EL there is a conflict.
We can still depend on hibernate-validator to support
JSR-303 in web apps because the EL implementation comes with
the container.

Fixes gh-5454

* pr/5557:
  Update README.adoc

Closes gh-5557

Add a @SpyBean annotation that can be used to create spies.

Fixes gh-5538

* pr/5553:
  Polish

Closes gh-5553

* gh-5406:
  Upgrade to Lombok 1.16.8

Closes gh-5406

* version-upgrades:
  Upgrade to Logback 1.1.6

Closes gh-5410

Closes gh-5408

Closes gh-5477

Rework the new testing support so that @SpringApplicationTest can be
used for standard integration tests, web integration tests with a
mock Servlet environment and web integration tests with an embedded
servlet container. This means that it a replacement for 1.3's
@IntegrationTest and @WebIntegrationTest and allows all
SpringApplication testing to be configured using a common annotation.

The old @IntegrationTest and @WebIntegrationTest along with their
supporting classes have been reinstated to their previous form (while
remaining deprecated). This should ensure that they continue to work
in 1.4 exactly as they did in 1.3 giving users a smooth path to
@SpringApplicationTest.

See gh-5477

Fixes gh-5547

It should have been in 68b83a8f but was excluded by gitignore.

See gh-3701

Previously, if loader.path directly specified a jar file that contained
nested archives (.zip or .jar), launching would fail unless those
nested archives were uncompressed. However, if loader.path specified a
directory that contained such a jar file the launch would succeed. This
was because the nested archives within the jar were ignored.

This commit updates PropertiesLauncher so that its behaviour in the
scenarios described above is consistent by not looking for archives
nested with a jar that’s be specified on loader.path. The javadoc for
loader.path has also been updated to make it clear that loader.path
can points to directories or jar files, bringing it into line with
the reference guide.

Closes gh-3701

Following changes to LaunchedURLClassLoader made in 87fe0b2a, it is
no longer necessary for the launcher to load MainMethodRunner via
reflection as both the app class loader that the launcher URL class
loader share the same MainMethodRunner class.

This commit takes advantage of this by updating Launcher to instantiate
MainMethodRunner directly rather than via reflection, removing one
source of possible exceptions in the launcher.

As the MainMethodRunner is now loaded directly and its class is shared
between the two class loaders, there’s no longer a need for it to
implement Runnable. This allows it to throw Exception from its run
method, rather than having to wrap any Exception in a RuntimeException.

Lastly, rather than catching any exception thrown from the launch,
Launcher and its subclasses have been updated to allow this exception
to be thrown from the main method. This allows the Exception to reach
the JVM, to be processed by our registered uncaught exception handler,
and to trigger the JVM’s standard processing for exiting due to a
failure. This removes the need for the Launcher itself to call
System.exit(1) and ensures that the exception is only output to the
console if it hasn’t been registered as a logged exception.

Closes gh-5358

Closes gh-5267

Previously, the documentation included hand-written tables for the
application, production, and technical starters.

This commit replaces the hand-written tables with tables that are
generated automatically from all of the starter poms, thereby ensuring
that the documentation is automatically kept up-to-date as starters
are added and removed. An extra column provided a link to each
starter's pom on GitHub has also been added to the table. This makes
it easier for users to see exactly what each starter contains.

Closes gh-5267

* pr/5532:
  Polish

Closes gh-5532

Closes gh-5309

* pr/5488:
  Upgrade Spring AMQP to 1.6.0.M2

Closes gh-5488

* pr/5521:
  Polish contribution
  Add `defaultValue` property in springProperty tag