Added user add functionality

scm-ui/src/components/Checkbox.js

@@ -0,0 +1,27 @@
+//@flow
+import React from "react";
+
+type Props = {
+  label: string,
+  onChange: boolean => void
+};
+class Checkbox extends React.Component<Props> {
+  onCheckboxChange = (event: SyntheticInputEvent<HTMLInputElement>) => {
+    this.props.onChange(event.target.checked);
+  };
+
+  render() {
+    return (
+      <div className="field">
+        <div className="control">
+          <label className="checkbox">
+            <input type="checkbox" onChange={this.onCheckboxChange} />{" "}
+            {this.props.label}
+          </label>
+        </div>
+      </div>
+    );
+  }
+}
+
+export default Checkbox;