Catch Excon Exception when requests timeout

[Gusymochis]

Excon throws and uncached exception when a timeout occurs:

-Heirloom version 0.12.1

/opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/socket.rb:176:in `select': Interrupt
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/socket.rb:176:in `rescue in block in connect'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/socket.rb:156:in `block in connect'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/socket.rb:152:in `each'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/socket.rb:152:in `connect'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/ssl_socket.rb:103:in `connect'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/socket.rb:32:in `initialize'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/ssl_socket.rb:8:in `initialize'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/connection.rb:361:in `new'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/connection.rb:361:in `socket'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/connection.rb:105:in `request_call'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/middlewares/mock.rb:42:in `request_call'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/middlewares/instrumentor.rb:22:in `request_call'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/middlewares/base.rb:15:in `request_call'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/middlewares/base.rb:15:in `request_call'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/middlewares/base.rb:15:in `request_call'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/connection.rb:244:in `request'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/middlewares/idempotent.rb:12:in `error_call'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/middlewares/base.rb:10:in `error_call'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/middlewares/base.rb:10:in `error_call'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/connection.rb:260:in `rescue in request'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/excon-0.25.3/lib/excon/connection.rb:220:in `request'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/fog-1.15.0/lib/fog/xml/sax_parser_connection.rb:36:in `request'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/fog-1.15.0/lib/fog/core/deprecated/connection.rb:18:in `request'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/fog-1.15.0/lib/fog/aws/simpledb.rb:181:in `request'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/fog-1.15.0/lib/fog/aws/requests/simpledb/list_domains.rb:28:in `list_domains'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/heirloom-0.12.1/lib/heirloom/aws/simpledb.rb:23:in `domains'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/heirloom-0.12.1/lib/heirloom/aws/simpledb.rb:27:in `domain_exists?'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/heirloom-0.12.1/lib/heirloom/catalog/verify.rb:12:in `catalog_domain_exists?'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/heirloom-0.12.1/lib/heirloom/catalog.rb:46:in `catalog_domain_exists?'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/heirloom-0.12.1/lib/heirloom/cli/shared.rb:173:in `ensure_catalog_domain_exists'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/heirloom-0.12.1/lib/heirloom/cli/catalog.rb:24:in `initialize'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/heirloom-0.12.1/lib/heirloom/cli.rb:30:in `new'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/heirloom-0.12.1/lib/heirloom/cli.rb:30:in `start'
    from /opt/heirloom/embedded/lib/ruby/gems/1.9.1/gems/heirloom-0.12.1/bin/heirloom:6:in `<top (required)>'
    from /usr/bin/heirloom:23:in `load'
    from /usr/bin/heirloom:23:in `<main>'