Merge pull request #189 from sparcs-kaist/#188-change-version-230-to-231

Change Version 2.3.0 to 2.3.1

pubspec.yaml

@@ -11,7 +11,7 @@ description: Online Timeplanner with Lectures Plus App @ KAIST
 # In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
 # Read more about iOS versioning at
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
-version: 2.3.0+21
+version: 2.3.1+21
 
 environment:
   sdk: ">=3.2.0 <4.0.0"