Merge pull request #378 from iamqizhao/coverall

improve readme
diff --git a/README.md b/README.md
index 94dc739..37b05f0 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 #gRPC-Go
 
-[![Build Status](https://travis-ci.org/grpc/grpc-go.svg)](https://travis-ci.org/grpc/grpc-go) [![GoDoc](https://godoc.org/google.golang.org/grpc?status.svg)](https://godoc.org/google.golang.org/grpc) [![Coverage Status](https://coveralls.io/repos/grpc/grpc-go/badge.svg?branch=master&service=github)](https://coveralls.io/github/grpc/grpc-go?branch=master)
+[![Build Status](https://travis-ci.org/grpc/grpc-go.svg)](https://travis-ci.org/grpc/grpc-go) [![GoDoc](https://godoc.org/google.golang.org/grpc?status.svg)](https://godoc.org/google.golang.org/grpc)
 
 The Go implementation of [gRPC](http://www.grpc.io/): A high performance, open source, general RPC framework that puts mobile and HTTP/2 first. For more information see the [gRPC Quick Start](http://www.grpc.io/docs/) guide.
 
@@ -20,11 +20,11 @@
 
 Constraints
 -----------
-The grpc package should only depend on standard Go packages and a short list of exceptions. A new addition to the list requires a discussion with gRPC-Go authors and consultants.
+The grpc package should only depend on standard Go packages and a small number of exceptions. If your contribution introduces new dependencies which are NOT in the [list](http://godoc.org/google.golang.org/grpc?imports), you need a discussion with gRPC-Go authors and consultants.
 
 Documentation
 -------------
-You can find more detailed documentation and examples in the [examples directory](examples/).
+See [API documentation](https://godoc.org/google.golang.org/grpc) for package and API descriptions and find examples in the [examples directory](examples/).
 
 Status
 ------