validate existing type annotations

Signed-off-by: Olamide Ojo <peterojoolamide@gmail.com>

Author: olamidepeterojo

CHANGELOG.md

@@ -18,7 +18,7 @@ All notable changes to the Zowe Client Python SDK will be documented in this fil
 
 ### Bug Fixes
 
-- Fixed Core SDK package referencing a non-existent version of Secrets SDK.
+- Fixed Core SDK package referencing a non-existent version of Secrets SDK. 
 
 ## `1.0.0-dev20`
 
@@ -28,6 +28,7 @@ All notable changes to the Zowe Client Python SDK will be documented in this fil
 
 ### Bug Fixes
 
+- Validate existing type annotations. [#321] (https://github.com/zowe/zowe-client-python-sdk/issues/321)
 
 ## `1.0.0-dev19`
 

pyproject.toml

@@ -9,3 +9,14 @@ style = "numpy"
 check-arg-order = false
 require-return-section-when-returning-nothing = false
 quiet = true
+
+[tool.mypy]
+files = "src"
+strict = true
+ignore_missing_imports = true
+namespace_packages = true
+explicit_package_bases = true
+disallow_untyped_defs = true
+warn_return_any = true
+warn_unused_ignores = true
+show_error_codes = true