ci(api_compatibility): add version 4.2.0 (#358)

* chore: Drop py36 from changelog

* fix: tox dependency < 4.0

* fix: adds api_compatibility_tests for 4.2.0

Co-authored-by: Shubham Chaturvedi <[email protected]>

Author: ShubhamChaturvedi7

api_compatibility_tests/compatibility-requirements/4.2.0

@@ -0,0 +1 @@
+aws-encryption-sdk-cli==4.2.0

api_compatibility_tests/tox.ini

@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    py{3,38}-awses_cli_{1.7.0,1.8.0,1.9.0,2.0.0,2.1.0,2.2.0,3.0.0,3.1.0,3.1.2,4.0.0,4.1.0}
+    py{3,38}-awses_cli_{1.7.0,1.8.0,1.9.0,2.0.0,2.1.0,2.2.0,3.0.0,3.1.0,3.1.2,4.0.0,4.1.0,4.2.0}
 
 [testenv:base-command]
 commands = pytest --basetemp={envtmpdir} -l test/ {posargs}
@@ -36,6 +36,7 @@ deps =
     awses_cli_3.1.2: -rcompatibility-requirements/3.1.2
     awses_cli_4.0.0: -rcompatibility-requirements/4.0.0
     awses_cli_4.1.0: -rcompatibility-requirements/4.1.0
+    awses_cli_4.2.0: -rcompatibility-requirements/4.2.0
     awses_cli_local: -e {env:AWSES_CLI_LOCAL_PATH}
 commands = 
     {[testenv:base-command]commands}