Update CHANGELOG

Author: znicholls

CHANGELOG.rst

@@ -8,6 +8,7 @@ master
 v0.6.1
 ------
 
+- (`#40 <https://github.com/znicholls/netcdf-scm/pull/40>`_) Upgrade to pyam v0.2.0
 - (`#38 <https://github.com/znicholls/netcdf-scm/pull/38>`_) Update to using openscm releases and hence drop Python3.6 support
 - (`#37 <https://github.com/znicholls/netcdf-scm/pull/37>`_) Adjusted read in of gregorian with 0 reference to give all data from year 1 back
 - (`#35 <https://github.com/znicholls/netcdf-scm/pull/35>`_) Fixed bug which prevented SCMCube from crunching to scm timeseries with default earth radius when areacella cube was missing