fix(overmind-devtools): fix issue with nested values not expanding

Author: christianalfoni

packages/node_modules/overmind-devtools/src/components/ValueInspector/index.tsx

@@ -10,7 +10,7 @@ const ValueInspector: SFC<Props> = ({ value, small }) => {
   const [expandedPaths, setExpandedPaths] = useState([])
 
   function onToggleExpand(path: string[]) {
-    const pathString = path.join('')
+    const pathString = path.join('.')
 
     if (expandedPaths.includes(pathString)) {
       setExpandedPaths(