Googletest renamed master to main today. (#1285)

Co-authored-by: Donald Aingworth <donald@midpointmarkets.org>

AUTHORS

diff --git a/AUTHORS b/AUTHORS
index 838dd4f..9128642 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -21,6 +21,7 @@
 Deniz Evrenci <denizevrenci@gmail.com>
 Dirac Research 
 Dominik Czarnota <dominik.b.czarnota@gmail.com>
+Donald Aingworth <donalds_junk_mail@yahoo.com>
 Eric Backus <eric_backus@alum.mit.edu>
 Eric Fiselier <eric@efcs.ca>
 Eugene Zhuk <eugene.zhuk@gmail.com>

CONTRIBUTORS

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 7489731..0f8ff7d 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -38,6 +38,7 @@
 Deniz Evrenci <denizevrenci@gmail.com>
 Dominic Hamon <dma@stripysock.com> <dominic@google.com>
 Dominik Czarnota <dominik.b.czarnota@gmail.com>
+Donald Aingworth <donalds_junk_mail@yahoo.com>
 Eric Backus <eric_backus@alum.mit.edu>
 Eric Fiselier <eric@efcs.ca>
 Eugene Zhuk <eugene.zhuk@gmail.com>

cmake/GoogleTest.cmake.in

diff --git a/cmake/GoogleTest.cmake.in b/cmake/GoogleTest.cmake.in
index 645da9b..bf89c47 100644
--- a/cmake/GoogleTest.cmake.in
+++ b/cmake/GoogleTest.cmake.in
@@ -38,7 +38,7 @@
     ExternalProject_Add(
       googletest
       GIT_REPOSITORY    https://github.com/google/googletest.git
-      GIT_TAG           master
+      GIT_TAG           main
       PREFIX            "${CMAKE_BINARY_DIR}"
       STAMP_DIR         "${CMAKE_BINARY_DIR}/stamp"
       DOWNLOAD_DIR      "${CMAKE_BINARY_DIR}/download"