update installation instructions; login no longer required

README.md

@@ -6,9 +6,7 @@ install.packages(c("devtools", "getPass"))
 
 Then, the ASPREE package itself can be installed using the following command:
 ```
-username <- "your_monash_username"
-devtools::install_git("https://gitlab.erc.monash.edu.au/aspree/aspree-r-package.git",
-    credentials = git2r::cred_user_pass(username, getPass::getPass()))
+devtools::install_git("https://gitlab.erc.monash.edu.au/aspree/aspree-r-package.git")
 ```
 You will be prompted for your Monash GitLab credentials before installation proceeds.