Update version numbers (#3430)

Author: WardBrian

.github/ISSUE_TEMPLATE.md

@@ -24,4 +24,4 @@ Describe what you expect the output to be. Knowing the correct behavior is also
 Provide any additional information here.
 
 #### Current Version:
-v2.39.0
+v2.40.0

lib/stan_math

@@ -38,7 +38,7 @@ PROJECT_NAME           = "Stan"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 2.39.0
+PROJECT_NUMBER         = 2.40.0
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a

src/doxygen/doxygen.cfg

@@ -12,7 +12,7 @@
 #endif
 
 #define STAN_MAJOR 2
-#define STAN_MINOR 39
+#define STAN_MINOR 40
 #define STAN_PATCH 0
 
 namespace stan {

src/stan/version.hpp

@@ -3,12 +3,12 @@
 
 TEST(Stan, macro) {
   EXPECT_EQ(2, STAN_MAJOR);
-  EXPECT_EQ(39, STAN_MINOR);
+  EXPECT_EQ(40, STAN_MINOR);
   EXPECT_EQ(0, STAN_PATCH);
 }
 
 TEST(Stan, version) {
   EXPECT_EQ("2", stan::MAJOR_VERSION);
-  EXPECT_EQ("39", stan::MINOR_VERSION);
+  EXPECT_EQ("40", stan::MINOR_VERSION);
   EXPECT_EQ("0", stan::PATCH_VERSION);
 }