add .idea to .gitignore (#2375)

## Changes
1. add ".idea" entry to ".gitgnore"

## Tests
1. manually checked that with this change files under .idea/ folder are
not staged for commit

Author: anton-107

.gitignore

@@ -25,6 +25,7 @@ coverage-acceptance.txt
 __pycache__
 *.pyc
 
+.idea
 .vscode/launch.json
 .vscode/tasks.json