update release notes

RELEASE_NOTES.txt

 Release 2.2.0 (01/31/2019)
 =============================
 - Added ESAF interfaces to APS DB service 
+- Moved all ESAF/BSS command line utilities to APS DB service 
+  - New command:
+    * list-beamlines 
 - Converted software to Python 3, but retained Python 2 compatibility
 - Introduced support for API pip and conda packages
 
@@ -12,6 +15,9 @@ Release 2.1.0 (12/31/2018)
 - Developed initial image receiver service and utilities that can accept
   Area Detector NTNDArray frames and save them into files; currently
   supported formats are SDDS, JSON, HDF5, and JPEG.
+  - New commands:
+    * start-image-receiver
+    * stop-image-receiver
 - Added new APS DB service for accessing beamline scheduling system 
 
 Release 2.0.0 (10/15/2018)