Add app bar

[clarkngo]

This PR resolves #2

Error 1

Failed to compile. 
./src/Components/AppBar.js 
Line 11:21:  'useStyles' is not defined  no-undef 
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Solution:
Changed to: const classes = makeStyles();

Error 2

Failed to compile.

./src/App.js
  Line 9:8:  'AppBar' is not defined  react/jsx-no-undef

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Solution:
Added: import AppBar from './Components/AppBar';

Error 3

Failed to compile. 
./src/Components/AppBar.js Module not found: Can't resolve '@material-ui/icons/Menu' in '/Users/clarkngo/dev/team-collaboration/word-tracking-app-repos/word-tracking-app/src/Components'

Solution:
npm install @material-ui/icons
Resource: mui/material-ui#10571