Merge pull request #194 from semaperepelitsa/readme_fix

Fix typo in readme (wrong update script name)

README.rdoc

@@ -107,8 +107,8 @@ MagLev source tree and other files. Change to that directory, then:
    run:
      ./install.sh
    If you've already run <tt>installMaglev.sh</tt> on the machine, then you
-   can use the upgrade script:
-     ./upgrade.sh
+   can use the update script:
+     ./update.sh
 
 To use MagLev, you need to run <tt>install.sh</tt> at least once.  After
 that, every time you <tt>git pull</tt>, you need to run <tt>update.sh</tt>
@@ -121,6 +121,6 @@ The installer/updater figures that out from the version.txt file.
 
 You'll have all the functionality of git, but unless you create a new
 clone for each release, you may be unable to revert to an earlier version.
-Why? The install/upgrade script creates a new copy of the MagLev data
+Why? The install/update script creates a new copy of the MagLev data
 repository including persistent kernel code. The scripts make one level of
 backup, but we are not providing migration scripts.