Update copyright for 2019

[dsernst]

1 character fix to update the copyright line from 2014-2018 to 2014-2019 💅

Here are the two places this value is used: https://github.com/webtorrent/webtorrent-desktop/search?q=APP_COPYRIGHT&unscoped_q=APP_COPYRIGHT

Happy new year everybody 🎉🍾🚀

[welcome]

🙌 Thanks for opening this pull request! You're awesome.

[trujamal]

General

• Does the code work?
• Is all the code easily understood?
• Does it conform to your agreed coding conventions?
• Is there any redundant or duplicate code?
• Is the code as modular as possible?
• Can any global variables be replaced?
• Is there any commented out code?
• Do loops have a set length and correct termination conditions?
• Do the names used in the program convey intent?

Performance

• Are there any obvious optimizations that will improve performance?
• Can any of the code be replaced with library or built-in functions?
• Can any logging or debugging code be removed?

Security

• Are all data inputs checked (for the correct type, length, format, and range) and encoded?
• Where third-party utilities are used, are returning errors being caught?
• Are output values checked and encoded?
• Are invalid parameter values handled?

Documentation

• Do comments exist and describe the intent of the code?
• Are all functions commented?
• Is any unusual behavior or edge-case handling described?
• Is the use and function of third-party libraries documented?
• Are data structures and units of measurement explained?
• Is there any incomplete code? If so, should it be removed or flagged with a suitable marker like ‘TODO’?

Testing

• Is the code testable? The code should be structured so that it doesn’t add too many or hide dependencies, is unable to initialize objects, test frameworks can use methods etc.
• Do tests exist, and are they comprehensive?
• Do unit tests actually test that the code is performing the intended functionality?
• Could any test code be replaced with the use of an existing API?

[welcome]

🎉 Congrats on getting your first pull request landed!