Show if finished

[SmartManoj]

solves #315

[SmartManoj]

Path: %USERPROFILE%\.vscode\extensions\formulahendry.code-runner-0.12.0\out\src\codeManager.js:447
For Insiders
Path: %USERPROFILE%\.vscode-insiders\extensions\formulahendry.code-runner-0.12.0\out\src\codeManager.js:447

I'm currently using

if (code !== 0) {
        this._outputChannel.appendLine("Finished with exit code=" + code + " in " + elapsedTime + " seconds");
} else {
        this._outputChannel.appendLine("Finished in " + elapsedTime + " seconds");   
}