Add ESLint to maintain code style. Add pre-commit hook to lint prior.

ESLint is used with the standard react plugin. It detects all kinds of
issues ranging from misspells, indentation, variable-naming, etc.
A pre-commit hook is added to git. Prior commiting, ESlint will run
to validate that everything is OK and the user will have the option
to fix it.

Signed-off-by: Sudhanshu Gautam <me@sudhanshug.com>

src/components/alert-dialog.js

@@ -0,0 +1,50 @@
+import {
+  Button,
+  Dialog,
+  DialogActions,
+  DialogContent,
+  DialogContentText,
+  DialogTitle,
+} from '@material-ui/core';
+import React from 'react';
+import PropTypes from 'prop-types';
+
+function AlertDialog({open, cancelHandler, acceptHandler, text, title, cancelComponent, acceptComponent}) {
+  return (
+    <Dialog
+      open={open}
+      onClose={cancelHandler}
+      aria-labelledby="alert-dialog-title"
+      aria-describedby="alert-dialog-description"
+    >
+      <DialogTitle
+        id="alert-dialog-title">{title}</DialogTitle>
+      <DialogContent>
+        <DialogContentText id="alert-dialog-description">
+          {text}
+        </DialogContentText>
+      </DialogContent>
+      <DialogActions>
+        <Button onClick={acceptHandler} color="primary">
+          {acceptComponent}
+        </Button>
+        <Button onClick={cancelHandler} color="secondary"
+          variant="contained" autoFocus>
+          {cancelComponent}
+        </Button>
+      </DialogActions>
+    </Dialog>
+  );
+}
+
+AlertDialog.propTypes = {
+  open: PropTypes.boolean,
+  cancelHandler: PropTypes.func,
+  acceptHandler: PropTypes.func,
+  text: PropTypes.string,
+  title: PropTypes.string,
+  cancelComponent: PropTypes.elementType,
+  acceptComponent: PropTypes.elementType,
+};
+
+export default AlertDialog;