Fix for Server Side Rendering

Merge: #19 fixed SSR

Add support for " ' " (single quote) key

Added key alias ' and quote

Avoid use of deprecated React life cycle methods

1. Use ComponentDidMount instead of ComponentWillMount()
2. Use ComponentDidUpdate instead of componentWillReceiveProps()

Support for '+' with modifier key

Add alias plus to support '+' key combined with modifier keys (e.g. ctrl+plus) #13

v1.5.0

Merged PR #11;
Updated documentation;
Updated dependencies;

v1.40

1. Add supports for more keys including Fn keys and modifier keys as common/single keys;
2. Add Eslint linting;
3. Upgrade Webpack to version 4;

v1.3.2

Add support for numeric keys on Window's numpad;
Update NPM dependencies to address security concerns;