DOC: update release notes

RELEASE_NOTES.txt

+OTB-v.5.10.1 - Changes since version 5.10.0 (March 8th, 2017)
+---------------------------------------------------------------
+
+* Packaging :
+  * Upgrade to GDAL 2.1.3, compatible with new format of Sentinel 2 products
+  * Upgrade of SertitObject external module with bugfixes
+
+* Bugfixes :
+
+  * Orfeo Toolbox (OTB)
+    * 0001364: Crash of Mapla.app v5.10.0 on MacOSX El Captain 10.11.5
+    * 0001365: Python wrapper OTB-5.8.0: @rpath problem on MacOSX El Captain 10.11
+    * 0001367: Monteverdi from the OTB standalone package for Mac OS X fails to run
+    * 0001366: OTB 5.10 : can't use extract ROI using bindings python
+
 OTB-v.5.10.0 - Changes since version 5.8.0 (February 14th, 2017)
 ---------------------------------------------------------------