Move ts-toolbelt into dependencies section

Author: Jed Mao

package-lock.json

@@ -51,7 +51,8 @@
   },
   "dependencies": {
     "loose-envify": "^1.4.0",
-    "symbol-observable": "^1.2.0"
+    "symbol-observable": "^1.2.0",
+    "ts-toolbelt": "^3.8.63"
   },
   "devDependencies": {
     "@babel/cli": "^7.5.0",
@@ -89,7 +90,6 @@
     "rollup-plugin-terser": "^5.1.1",
     "rollup-plugin-typescript2": "^0.24.0",
     "rxjs": "^6.5.2",
-    "ts-toolbelt": "^3.8.63",
     "typescript": "^3.5.3",
     "typings-tester": "^0.3.2"
   },