Update charm++ latest version

Author: adityapb

content/download.html

@@ -13,7 +13,7 @@
   <h1>Downloads</h1>
   <h2 id='charm_source'>Charm++</h2>
 
-  <p>Latest release version: <a href="http://charm.cs.illinois.edu/distrib/charm-7.0.0.tar.gz">Charm++ v7.0.0 (tar.gz)</a></p>
+  <p>Latest release version: <a href="http://charm.cs.illinois.edu/distrib/charm-8.0.0.tar.gz">Charm++ v8.0.0 (tar.gz)</a></p>
   <p>Latest dev version: <a href="http://charm.cs.illinois.edu/autobuild/cur/charm_src.tar.gz">Nightly Snapshot (tar.gz)</a></p>
 
   <p>The latest development version of Charm++ can be downloaded directly from our