component/firefox: new version 60.0.2esr (default remain 52)

This is next ESR version, but for now it still have to be used
explicitly.

component/firefox/buildout.cfg

@@ -47,6 +47,11 @@ script =
   ))
     os.fchmod(f.fileno(), 0o755)
 
+[firefox-wrapper-60]
+<= firefox-wrapper
+wrapper-name = firefox-60
+part = ${firefox-60:location}
+
 [firefox-wrapper-52]
 <= firefox-wrapper
 wrapper-name = firefox-52
@@ -66,6 +71,12 @@ part = ${firefox-51:location}
 # would not be created.
 <= firefox-52
 
+[firefox-60]
+<= firefox-download
+version = 60.0.2esr
+i686-md5sum = ce7c80716036dfb5c2fb1ca2538556ff
+x86_64-md5sum = 6fe25d9a3fcc82670320242c9047d1da
+
 [firefox-52]
 <= firefox-download
 version = 52.9.0esr