Fix order size issue and update PubNub

• Fix amount of order size issue due to bitflyer's order amount available degits.
• Remove pln and keepRate from Swift Equatable. These are dynamic changed by order fetching and causes confusion.
• Update PubNub framework to latest version.

Fix Name of import class and Add GetHealthStateRequest

• Rename BitFyler to BitFlyer.
• Add GetHealthStateRequest