Fix data race in Addrs

Signed-off-by: Jonathan Rudenberg <jonathan@titanous.com>
Move tests to a separate package

Signed-off-by: Jonathan Rudenberg <jonathan@titanous.com>
Add discoverd-powered HTTP client and dialer

Signed-off-by: Jonathan Rudenberg <jonathan@titanous.com>
Merge pull request #20 from flynn/http-client

Add discoverd-powered HTTP client and dialer