chore(deps): update overlay (jquense#1301)

* Update react-overlays dependency and usage

* unnecessary key

* Fix ref reference for proper offset calcs

* Proper ref forwarding

* Add notes and rebuild examples

* forgot the examples

* Add proper PropType for popperRef

* Import change, according to maintainer feedback

* Merge latest updates from master and rebuild examples

* Update react-overlays dependency and usage

* Fix ref reference for proper offset calcs

* Proper ref forwarding

* Add notes and rebuild examples

* forgot the examples

* Add proper PropType for popperRef

* Import change, according to maintainer feedback

* Merge latest updates from master and rebuild examples

* Updates from new merge, and updated examples build

* Update yarn.lock with recent updates, and rebuild examples

* Removed duplicate key in props

.size-snapshot.json

@@ -1,25 +1,25 @@
 {
   "./dist/react-big-calendar.js": {
-    "bundled": 471349,
-    "minified": 153211,
-    "gzipped": 42302
+    "bundled": 561388,
+    "minified": 171351,
+    "gzipped": 50367
   },
   "./dist/react-big-calendar.min.js": {
-    "bundled": 414053,
-    "minified": 136181,
-    "gzipped": 38428
+    "bundled": 497725,
+    "minified": 152002,
+    "gzipped": 45855
   },
   "dist/react-big-calendar.esm.js": {
-    "bundled": 168039,
-    "minified": 80688,
-    "gzipped": 19864,
+    "bundled": 169329,
+    "minified": 81452,
+    "gzipped": 20069,
     "treeshaked": {
       "rollup": {
-        "code": 62227,
-        "import_statements": 1470
+        "code": 62945,
+        "import_statements": 1466
       },
       "webpack": {
-        "code": 65735
+        "code": 66463
       }
     }
   }