Feature/async await

[cpwood]

What does this implement/fix? Explain your changes.

• Uses ES6 Javascript throughout;
• Removed callback spaghetti;
• Removed redundant code;
• Refactored serial comms code code;
• Normalised naming conventions to PascalCase for classes and camelCase for methods and variables;
• Uses let and const instead of var;
• Semi-colons now used throughout;
• Generally beautified code.

Does this close any currently open issues?

Fixes #35