Merge pull request #80 from nextleap-project/release-0.10

updating changelog for 0.10.0 release

CHANGELOG.rst

@@ -1,3 +1,24 @@
+0.10.0 (Incorporating feedback and finalizing)
+----------------------------------------------
+
+- include feedback received after sharing countermitm
+  with the messaging@moderncrypto.org mailing list:
+
+  - build verified group and history verification
+    based on contact verification.
+
+  - prevent replay attacks
+
+- improve readability and clarity in the entire document.
+  (Wouter Lueks)
+
+- refine and document the interaction of encryption
+  with verified and opportunistic Autocrypt keys.
+
+- address device loss in a verified group scenario.
+
+- add presentation slides for OpenPGP Summit 2018 in Brussels.
+
 
 0.9.1 (typo/word/format-fixing)
 -------------------------------