added necessary Go version to compile from source to Readme
@@ -170,7 +170,7 @@ The requested tile will be encode a layer with the `name` value set to `debug` a
## Building from source
-Tegola is written in [Go](https://golang.org/). To build tegola from source, make sure you have Go installed and have cloned the repository to your `$GOPATH` or `$GOROOT`. Navigate to the repository then run the following commands:
+Tegola is written in [Go](https://golang.org/) and requires Go 1.7+ to compile from source. To build tegola from source, make sure you have Go installed and have cloned the repository to your `$GOPATH` or `$GOROOT`. Navigate to the repository then run the following commands:
```bash
cd cmd/tegola/
