Merge pull request #4530 from bridadan/verbose_example_build

Enable verbose builds when running example build tests

tools/test/examples/examples_lib.py

@@ -356,7 +356,7 @@ def compile_repos(config, toolchains, targets, examples):
                                                                 example['features']):
                     print("Compiling %s for %s, %s" % (name, target, toolchain))
                     proc = subprocess.Popen(["mbed-cli", "compile", "-t", toolchain,
-                                             "-m", target, "--silent"])
+                                             "-m", target, "-v"])
                     proc.wait()
                     example_summary = "{} {} {}".format(name, target, toolchain)
                     if proc.returncode: