Merge pull request #1 from ahardy55/users

Users
add workout history and exercise history migrations
create history models
add model associations based on addition of new tables/models: workout history and exercise history
changes to schema.rb based on weight, reps, rest_time
rspec tests for user model validations (email uniqueness test does not currently work, tho email uniqueness validation does work)
add rspec for exercise and workout validations
add more tests for validations
modified data tables
Merge pull request #7 from ahardy55/models

Add workout history and exercise migrations
Create history models
Add model associations based on addition of new tables/models
Add weight, reps, rest_time to schema.rb
Write Rspec tests for user model validations
Write Rspec tests for exercise and workout validations