Assert should fail gracefully, and prevent stopping of all test execution

[dawnTestCode]

In this case, upon first npm test after successful npm install:

> secret-share@1.0.0 test /Users/dcode/dev/unspecified/Coval.js
> mocha



  Agent
    ✓ Should identify as client when cast as client
------------ identity type Identity { type: 'identity' }
    ✓ Should identify as identity when cast as identity
    ✓ Should identify of type Unloq as identity when cast as identity of Unloq
    ✓ Should identify as server when cast as server
    ✓ Should identify as generic when not cast

  Coval.js
    - should enforce https everywhere

  Dat
    Share
      ✓ should resolve provided path correcty (141ms)
      ✓ should allow for multiple shares with unique keys (96ms)
      ✓ should allow for downloading a share (83ms)
      ✓ should error when no shares exist for key (8039ms)
Assertion failed: (!uv__io_active(&handle->io_watcher, POLLIN | POLLOUT)), function uv__udp_finish_close, file ../deps/uv/src/unix/udp.c, line 67.