fix proptypes

src/js/components/PostCommentsLink.jsx

@@ -12,7 +12,7 @@ const CommentsLink = ({ id, commentCount }) => (
     </span>
 );
 
-CommentsLink.PropTypes = {
+CommentsLink.propTypes = {
     id: PropTypes.string,
     commentCount: PropTypes.number
 };

src/js/components/PostCreatorLink.jsx

@@ -9,7 +9,7 @@ const PostCreatorLink = ({ creator }) => (
     </span>
 );
 
-PostCreatorLink.PropTypes = {
+PostCreatorLink.propTypes = {
     creator: PropTypes.string
 };
 

src/js/components/PostDeleteLink.jsx

@@ -9,7 +9,7 @@ const PostDeleteLink = ({ post }) => (
     </span>
 );
 
-PostDeleteLink.PropTypes = {
+PostDeleteLink.propTypes = {
     post: PropTypes.object
 };
 

src/js/components/PostLink.jsx

@@ -12,7 +12,7 @@ const PostLink = ({ url, title }) => (
     </div>
 );
 
-PostLink.PropTypes = {
+PostLink.propTypes = {
     url: PropTypes.string,
     title: PropTypes.string
 };

src/js/components/PostTimeAgo.jsx

@@ -9,7 +9,7 @@ const PostTimeAgo = ({ time }) => (
     </span>
 );
 
-PostTimeAgo.PropTypes = {
+PostTimeAgo.propTypes = {
     time: PropTypes.string
 };