Create config object levels

[Amertz08]

Overall

• Create config.py that has 4 classes. Config, DevelopmentConfig, TestingConfig, ProductionConfig All should inherit from Config
• Create dict config that has development, testing, production, default config levels as keys, Config objects as values. default should be DevelopmentConfig
• Integrate loading config into application factory

Config

• init_app static method that takes in app and does nothing i.e. pass
• SECRET_KEY = RANDOM_HASH

DebugConfig

• DEBUG = True

TestingConfig

• TESTING = True

ProductionConfig

• pass for now

Depends on #51 being finished