Don't fail CI status for small coverage decreases

Author: rth

.codecov.yml

@@ -0,0 +1,15 @@
+coverage:
+
+  status:
+    project:                   # measuring the overall project coverage
+      default:                 # context, you can create multiple ones with custom titles
+        enabled: yes           # must be yes|true to enable this status
+        threshold: 0.5         # allowed to drop X% and still result in a "success" commit status
+
+    patch:                     # pull requests only: this commit status will measure the
+                               # entire pull requests Coverage Diff. Checking if the lines
+                               # adjusted are covered at least X%.
+      default:
+        enabled: yes           # must be yes|true to enable this status
+        threshold: 0.5         # allowed to drop X% and still result in a "success" commit status
+