Merge pull request #14 from sgerrand/installation-docs-update

Update installation documentation

Author: sgerrand

README.md

@@ -11,12 +11,12 @@ See the [releases page][releases] for the latest download links.
 ## Installing
 
 The current installation method for these packages is to pull them in using
-`wget` or `curl` and install the local file with the `--allow-untrusted` option
-to `apk`:
+`wget` or `curl` and install the local file with `apk`:
 
-    apk --no-cache add ca-certificates
-    wget https://github.com/sgerrand/alpine-pkg-R/releases/download/3.2.5-r0/R-3.2.5-r0.apk
-    apk --allow-untrusted add R-3.2.5-r0.apk
+    apk --no-cache add ca-certificates wget
+    wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://raw.githubusercontent.com/sgerrand/alpine-pkg-R/master/sgerrand.rsa.pub
+    wget https://github.com/sgerrand/alpine-pkg-R/releases/download/3.3.1-r0/R-3.3.1-r0.apk
+    apk add R-3.3.1-r0.apk
 
 [r-project]: http://www.r-project.org/
 [releases]: https://github.com/sgerrand/alpine-pkg-R/releases/