best, but suboptimal, attempt to stop tf from borking the test summary output

Author: topepo

tests/testthat/test_aaaa.R

@@ -0,0 +1,6 @@
+# keras is pretty tenacious about writing output to the R session. By default
+# this gets inserted into the test results. To make this less hideous, we
+# try to trigger the output here so that it shows up at the top of the testing.
+
+Sys.setenv(TF_CPP_MIN_LOG_LEVEL = '3')
+try(keras:::backend(), silent = TRUE)