fix: add prop-types to dependencies list (#157)

The dependency is needed by `create-react-context` in version of React lower than 16

Author: TrySound

package.json

@@ -61,6 +61,7 @@
     "babel-runtime": "6.x.x",
     "create-react-context": "^0.2.1",
     "popper.js": "^1.14.1",
+    "prop-types": "^15.6.1",
     "warning": "^3.0.0"
   },
   "devDependencies": {

yarn.lock

@@ -5176,7 +5176,7 @@ promise@^7.1.1:
   dependencies:
     asap "~2.0.3"
 
-prop-types@^15.6.0:
+prop-types@^15.6.0, prop-types@^15.6.1:
   version "15.6.1"
   resolved "https://registry.yarnpkg.com/prop-types/-/prop-types-15.6.1.tgz#36644453564255ddda391191fb3a125cbdf654ca"
   dependencies: