Rename checkpoint() to laxCheckpoint(), rename strictCheckpoint() to checkpoint()

[julianladisch]

The vast majority of asynchronous implementations require a strict checkpoint. Therefore the default checkpoint() function should return a strict checkpoint.

This is an API change that may break existing code. However, https://vertx.io/docs/vertx-junit5/java/ says: "Warning | This module has Tech Preview status, this means the API can change between versions."

[julianladisch]

Thanks @jponge, I've reviewed the 4 files in src/main/asciidoc and src/main/java/examples:

• index.adoc: No change needed because the example code is a {@link examples.Examples#checkpointing}.
• Examples.java: It has checkpoint usage in checkpointing(Vertx vertx, VertxTestContext testContext) only. No change needed. testContext.checkpoint() and testContext.checkpoint(10) look the same but the underlying checkpoint has changed from weak checkpoint to strong checkpoint. However that unit test is still successful. The code is a copy of src/test/java/io/vertx/junit5/IntegrationTest.java#start_and_request_http_server_with_checkpoints that succeeds.
• LifecycleExampleTest.java: Doesn't contain any checkpoint.
• RxJava2Test.java: It contains one checkpoint: testContext.strictCheckpoint(10). This has been changed to testContext.checkpoint(10) in yesterday's commit ede5756.

[jponge]

Ok thanks @julianladisch .

How about #49 and this BTW?

[julianladisch]

49 and this pull request are independent of each other. There javadoc of #49 is still correct if this pull request gets merged.