Merge pull request #39 from tpenn/chapter1-edits

Chapter1 edits

Merge pull request #34 from LaunchCodeEducation/ch-20-rest

Ch 20 rest

Merge pull request #35 from LaunchCodeEducation/chapter18

Chapter 18: Relationships and ORM

added next-steps for enums chapter in java

updated key terms section, fixed broken relref

Merge pull request #27 from LaunchCodeEducation/chapter15

Chapter 15: Model Validation

added next steps, updated key terms section

added sentence to key terms about making notes for key-terms

proper naming conventions for java-web-dev-projects

Applying consistent formatting to all assignments