Fix EEA SSL error

[sruti]

Problem

The EEA source recently switched to https, but the certificate chain was misconfigured, resulting in this error, causing fetch to fail:

events.js:174
      throw er; // Unhandled 'error' event
      ^

Error: unable to verify the first certificate
    at TLSSocket.onConnectSecure (_tls_wrap.js:1088:34)
    at TLSSocket.emit (events.js:198:13)
    at TLSSocket._finishInit (_tls_wrap.js:666:8)
Emitted 'error' event at:
    at Request.onRequestError (/Users/sruti/Desktop/openaq/openaq-fetch/node_modules/request/request.js:881:8)
    at ClientRequest.emit (events.js:203:15)
    at TLSSocket.socketErrorListener (_http_client.js:401:9)
    at TLSSocket.emit (events.js:198:13)
    at emitErrorNT (internal/streams/destroy.js:91:8)
    at emitErrorAndCloseNT (internal/streams/destroy.js:59:3)
    at process._tickCallback (internal/process/next_tick.js:63:19)

Fix

• Added correct certificate chain and attached it to the request using ssl-root-cas module
• Switched source urls to https