tools/codecov.yml: add

Add configuratio file for codecov.io

.travis.yml

@@ -27,7 +27,7 @@ script:
   - make presubmit
 
 after_success:
-  - bash <(curl -s https://codecov.io/bash)
+  - curl -s https://codecov.io/bash | bash -s - -y tools/codecov.yml
 
 # If the build fails because some code in not formatted, it's nice to see the diffs after formatting.
 after_failure:

Makefile

@@ -335,7 +335,7 @@ presubmit_parallel: test test_race arch
 
 test: descriptions
 ifeq ("$(TRAVIS)$(shell go version | grep 1.13)", "true")
-	# Collect coverage report for codecov.io when testing Go 1.12 on travis (uploaded in .travis.yml).
+	# Collect coverage report for codecov.io when testing Go 1.14 on travis (uploaded in .travis.yml).
 	env CGO_ENABLED=1 $(GO) test -short -coverprofile=coverage.txt ./...
 else
 	# Executor tests use cgo.

tools/codecov.yml

@@ -0,0 +1,13 @@
+# See https://docs.codecov.io/docs/codecovyml-reference
+# Validate with curl --data-binary @tools/codecov.yml https://codecov.io/validate
+
+coverage:
+  precision: 0
+  round: nearest
+  range: "50...75"
+
+coverage:
+  status:
+    project:
+      default:
+        threshold: 1%