Merge pull request #61 from milvus-ci-robot/0.5.0

Add Codecov Yaml file

Former-commit-id: 38a550f94fc574e689dd8bfc1783ae3d67289ff1

codecov.yaml

+#Configuration File for CodeCov
+coverage:
+  precision: 2
+  round: down
+  range: "70...100"
+
+  status:
+    project: on
+    patch: yes
+    changes: no
+
+comment:
+  layout: "header, diff, changes, tree"
+  behavior: default