Add working previews for each view

MobileFort/MobileFort/Common.swift

@@ -43,3 +43,24 @@ struct Post: Decodable, Identifiable {
         }
     }
 }
+
+let testMedia = Media(id: 0,
+                      url: "https://homepages.cae.wisc.edu/~ece533/images/airplane.png")
+
+let fooPost = Post(id: 0,
+                   title: "Foo",
+                   content: "",
+                   postType: .picture,
+                   media: [testMedia],
+                   username: "foobar",
+                   originalUsername: nil,
+                   originalPost: nil)
+
+let fooPostReblog = Post(id: 1,
+                         title: nil,
+                         content: "",
+                         postType: .picture,
+                         media: [testMedia],
+                         username: "foobar",
+                         originalUsername: "foobar2",
+                         originalPost: nil)

MobileFort/MobileFort/PostView.swift

@@ -38,7 +38,6 @@ struct PostView: View {
 
 struct PostView_Previews: PreviewProvider {
     static var previews: some View {
-        //PostView()
-        Text("Hello, world!")
+        return PostView(post: fooPost)
     }
 }

MobileFort/MobileFort/ProfileView.swift

@@ -39,7 +39,6 @@ struct ProfileView: View {
 
 struct ProfileView_Previews: PreviewProvider {
     static var previews: some View {
-        //ProfileView()
-        Text("Hello, world!")
+        return ProfileView(username: "foobar", posts: [fooPost, fooPostReblog])
     }
 }