Replace gt dependency with lt

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: gsDesign2
 Title: Group Sequential Design with Non-Constant Effect
-Version: 1.1.9
+Version: 1.1.10
 Authors@R: c(
     person("Keaven", "Anderson", email = "keaven_anderson@merck.com", role = c("aut")),
     person("Yujie", "Zhao", email = "yujie.zhao@merck.com", role = c("aut", "cre")),
@@ -43,7 +43,7 @@ Imports:
     data.table,
     dplyr,
     gsDesign,
-    gt,
+    lt,
     methods,
     mvtnorm,
     npsurvSS (>= 1.1.0),
@@ -68,4 +68,4 @@ VignetteBuilder:
 LinkingTo:
     Rcpp
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.3.3
+Config/roxygen2/version: 8.0.0

NAMESPACE

@@ -1,10 +1,9 @@
 # Generated by roxygen2: do not edit by hand
 
-S3method(as_gt,fixed_design_summary)
-S3method(as_gt,gs_design_summary)
-S3method(as_gt,simtrial_gs_wlr)
 S3method(as_rtf,fixed_design_summary)
 S3method(as_rtf,gs_design_summary)
+S3method(lt::lt,fixed_design_summary)
+S3method(lt::lt,gs_design_summary)
 S3method(print,fixed_design)
 S3method(print,gs_design)
 S3method(summary,fixed_design)

NEWS.md

@@ -1,3 +1,9 @@
+# gsDesign2 1.2.0
+
+## Major changes
+
+- The (heavy) **gt** dependency has been replaced with the lightweight **lt** package. The `as_gt()` function is deprecated in favor of `lt::lt()`. S3 methods for `lt()` are provided for `fixed_design_summary` and `gs_design_summary` objects. There are no significant visual changes in the HTML tables.
+
 # gsDesign2 1.1.9
 
 ## New features