I have same issue.
can’t download 1.4.13 --> hangs on 0 secs left 178/178 mb
can’t download appium.dmg --> hangs on 0 secs left 178/178 mb
can’t download 1.4.8 --> hangs on 0 secs left 214/214 mb
OS X El Capitan. Version: 10.11.3 (15D21)
Browser - Chrome