Update changelog and upload to unstable

debian/changelog

+mariadb-10.1 (10.1.20-2) unstable; urgency=low
+
+  [ Otto Kekäläinen ]
+  * Upload to unstable
+  * Previous version string should had been ~exp1, thus this
+    first upload to unstable is -2 and not -1 as normal
+  * Disable test suite temporairly due to false regressions
+
+  [ Dieter Adriaenssens ]
+  * fix Vcs-git link format and repo name
+  * update 10.0 to 10.1 in README files
+
+  [ Vicențiu Ciorbaru ]
+  * Fix mips missing atomics primitives
+
+ -- Otto Kekäläinen <otto@debian.org>  Sat, 24 Dec 2016 09:54:59 +0200
+
 mariadb-10.1 (10.1.20-1) experimental; urgency=low
 
   * Upgrade package to new MariaDB 10.1.x series: