ruby: disable IPv6

Addrinfo.getaddrinfo does not able to resolve IP address correctly until disabling IPv6 feature.

Fixed #516

Signed-off-by: Takuya ASADA <syuu@cloudius-systems.com>
ruby-rails-example: drop thin

Since #516 fixed, we don't need to install thin web server anymore.

Signed-off-by: Takuya ASADA <syuu@cloudius-systems.com>
ruby-sinatra-example: drop thin

Since #516 fixed, we don't need to install thin web server anymore.

Signed-off-by: Takuya ASADA <syuu@cloudius-systems.com>