Added codecov, Added badges

Author: jwillbold

.codecov.yml

@@ -0,0 +1,13 @@
+comment:
+  layout: "reach, diff, flags, files"
+  behavior: default
+  require_changes: false
+  branches:
+    - "!dev"
+
+codecov:
+  require_ci_to_pass: true
+
+# The slog_serde file is more like a dependency, so ignore it.
+ignore:
+  - src/slog_serde.rs

README.md

@@ -1,5 +1,9 @@
+[![Build Status](https://travis-ci.com/jwillbold/slog_mongodb.svg?token=hPh87VpFt3MQPwdySdkS&branch=master)](https://travis-ci.com/jwillbold/slog_mongodb)
+[![codecov](https://codecov.io/gh/jwillbold/slog_mongodb/branch/master/graph/badge.svg)](https://codecov.io/gh/jwillbold/slog_mongodb)
+
 # slog_mongodb
 
+MongoDB extension for the Rust logging library [slog-rs](https://github.com/slog-rs/slog).
 Serializes the [slog](https://github.com/slog-rs/slog) key-value pairs to [BSON](https://github.com/mongodb/bson-rust) and stores it in a [MongoDB collection](https://github.com/mongodb/mongo-rust-driver).
 To reduce the stress on the database, the logged messages are buffered and only sent in configurable time intervals.