change makepackage.m to check version number

previous behavior was that it set the version number every time,
which could cause pain with commits not matching up.

makepackage.m

@@ -16,5 +16,7 @@ end
 [~,outfname,~] = fileparts(fname);
 outfname = join([outfname, build, '.mltbx'], '');
 
-matlab.addons.toolbox.toolboxVersion(fname,version)
-matlab.addons.toolbox.packageToolbox(fname,outfname)
\ No newline at end of file
+if ~strcmp(matlab.addons.toolbox.toolboxVersion(fname), version)
+    error('toolbox version and specified version do not match')
+end
+matlab.addons.toolbox.packageToolbox(fname,outfname)