release: Update package.xml version to 1.2.0

Author: proyan

package.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <package format="3">
   <name>pycppad</name>
-  <version>1.1.0</version>
+  <version>1.2.0</version>
   <description>Python bindings for CppAD and CppADCodeGen using Boost.Python</description>
   <maintainer email="[email protected]">Rohan Budhiraja</maintainer>
   <author>Rohan Budhiraja</author>