Updated math lesson_settings.json files

[Ethan-Arrowood]

Issue & Comment Ref: #8 (comment)

1. Structure of lesson_settings.json file is as follows:

{
  "lesson_title": "Example Title",
  "chapter_number": 1,
  "lesson_number": 3,
  "id":"59289aff2a0e7d815626f329"
}

2. The lesson_settings.json file should reflect the challenge directory title. The title for the example object above would be: 1.3.Example_Title
3. Note we are removing title underscores in the settings file.

Important
How to generate lesson ids:

1. In your terminal start up mongoDB by typing: mongo
2. Next type: ObjectId() it should return an object like so: ObjectId("59289aff2a0e7d815626f329")
3. Copy and paste the generated string and use that in your lesson_settings.json file.

Coming up:

I'm currently working on a script that auto generates the challenge.json file. I'm going to include an lesson id check to verify all lessons have different ids. [Down The Road] when users submit challenge fixes or new challenges we will make them submit an updated challenges.json file that passes the id check method.