Merge pull request #1633 from ijc/go1.9

Update docs with go 1.9 requirement.

BUILDING.md

@@ -9,7 +9,7 @@ In first you need to setup your Go development environment. You can follow this
 guideline [How to write go code](https://golang.org/doc/code.html) and at the
 end you need to have `GOPATH` and `GOROOT` set in your environment.
 
-Current containerd requires Go 1.8.x or above.
+Current containerd requires Go 1.9.x or above.
 
 At this point you can use `go` to checkout `containerd` in your `GOPATH`:
 

README.md

@@ -154,7 +154,7 @@ err := task.Start(context)
 
 To build the daemon and `ctr` simple test client, the following build system dependencies are required:
 
-* Go 1.8.x or above (requires 1.8 due to use of golang plugin(s))
+* Go 1.9.x or above
 * Protoc 3.x compiler and headers (download at the [Google protobuf releases page](https://github.com/google/protobuf/releases))
 * Btrfs headers and libraries for your distribution. Note that building the btrfs driver can be disabled via build tag removing this dependency.
 

docs/getting-started.md

@@ -7,7 +7,7 @@ However, if you want to integrate containerd into your project we have an easy t
 In this guide we will pull and run a redis server with containerd using the client package.
 We will assume that you are running a modern linux host for this example with a compatible build of `runc`.
 Please refer to [RUNC.md](/RUNC.md) for the currently supported version of `runc`.
-This project requires Go 1.8.x or above.
+This project requires Go 1.9.x or above.
 If you need to install Go or update your currently installed one, please refer to Go install page at https://golang.org/doc/install.
 
 ## Starting containerd