Discord invite expired

[Zach Hoffman]

The Discord invite in CONTRIBUTING.md has expired.

Output of bower -v && npm -v && node -v:

1.8.8
6.14.5
v14.2.0

Additional environment details (proxy, private registry, etc.):
Discord desktop client

Steps to reproduce the issue:

1. Open Discord
2. Add a server
3. Paste invite

Describe the results you received:
Recieved message:

(The invite is invalid or has expired)

Describe the results you expected:
Joining the Bower Discord

[Adam Stankiewicz]

we discontinued discord server because no one was using it, I'll remove reference