Maintainer: ‘Juan Xiong <xiongjuan2000@gmail.com>’

No Authors@R field in DESCRIPTION.
Please add one, modifying
  Authors@R: c(person(given = "Juan",
                      family = "Xiong",
                      role = c("aut", "cre"),
                      email = "xiongjuan2000@gmail.com"),
               person(given = "Wenqing",
                      family = "He",
                      role = "aut",
                      email = "whe@stats.uwo.ca"),
               person(given = c("Grace", "Y."),
                      family = "Yi",
                      role = "aut",
                      email = "yyi@uwaterloo.ca"))
as necessary.

The Title field is just the package name: provide a real title.
Maintainer: ‘Juan Xiong <xiongjuan2000@gmail.com>’

No Authors@R field in DESCRIPTION.
Please add one, modifying
  Authors@R: c(person(given = "Juan",
                      family = "Xiong",
                      role = c("aut", "cre"),
                      email = "xiongjuan2000@gmail.com"),
               person(given = "Wenqing",
                      family = "He",
                      role = "aut",
                      email = "whe@stats.uwo.ca"),
               person(given = c("Grace", "Y."),
                      family = "Yi",
                      role = "aut",
                      email = "yyi@uwaterloo.ca"))
as necessary.

The Title field is just the package name: provide a real title.