Install PostgresVersion.pm

A lamentable oversight on my part meant that when PostgresVersion.pm was
added in commit 4c4eaf3 provision to install it was not added to the
Makefile, so it was not installed along with the other perl modules.

Author: adunstan

src/test/perl/Makefile

@@ -23,11 +23,13 @@ install: all installdirs
 	$(INSTALL_DATA) $(srcdir)/SimpleTee.pm '$(DESTDIR)$(pgxsdir)/$(subdir)/SimpleTee.pm'
 	$(INSTALL_DATA) $(srcdir)/RecursiveCopy.pm '$(DESTDIR)$(pgxsdir)/$(subdir)/RecursiveCopy.pm'
 	$(INSTALL_DATA) $(srcdir)/PostgresNode.pm '$(DESTDIR)$(pgxsdir)/$(subdir)/PostgresNode.pm'
+	$(INSTALL_DATA) $(srcdir)/PostgresVersion.pm '$(DESTDIR)$(pgxsdir)/$(subdir)/PostgresVersion.pm'
 
 uninstall:
 	rm -f '$(DESTDIR)$(pgxsdir)/$(subdir)/TestLib.pm'
 	rm -f '$(DESTDIR)$(pgxsdir)/$(subdir)/SimpleTee.pm'
 	rm -f '$(DESTDIR)$(pgxsdir)/$(subdir)/RecursiveCopy.pm'
 	rm -f '$(DESTDIR)$(pgxsdir)/$(subdir)/PostgresNode.pm'
+	rm -f '$(DESTDIR)$(pgxsdir)/$(subdir)/PostgresVersion.pm'
 
 endif