update readme

README.md

@@ -13,8 +13,9 @@ The package is working but might change at any time.
 ## Installation
 
 ```R
+#devtools::install_github("r-lib/devtools")
 library("devtools")
-devtools::install_git("git@git.nilu.no:rextapi/eipar.git")
+devtools::install_git("https://git.nilu.no/rextapi/eipar.git")
 ```
 
 ## Usage