Messy testthat output due to 3e

[AshesITR]

From ?testthat::expect_warning:

In the 3rd edition, these functions match (at most) a single condition. All additional and non-matching (if regexp or class are used) conditions will bubble up outside the expectation. If these additional conditions are important you'll need to catch them with additional expect_message()/expect_warning() calls; if they're unimportant you can ignore with suppressMessages()/suppressWarnings().

This causes a lot of noise in the output of devtools::test() on master atm.

[AshesITR]

Here is what devtools::test() interactively produces:

• test-backport_linter.R:9 Warning bubbles
• test-cache.R produces output
• test-cache.R:91 Two warnings bubble
• test-ci.R:39 Deprecation warning for with_mock()
• test-ci.R:52 Deprecation warning for with_mock()
• test-dir_linters.R produces output
• test-expect_lint.R produces output
• test-expect_lint.R:59 calls RStudio API
• test-knitr_formats.R produces output
• test-lint_package.R produces output
• test-methods.R:117 Deprecation warning for with_mock()
• test-object_usage_linter.R produces output
• test-rstudio_markers.R:97 Deprecation warning for with_mock()