Adds support for HEAD method. Removes rest-client gem.

Gem is removed because it does not support HTTP HEAD request method.

Adds support for HEAD method via Ruby stdlib class Net::HTTP.

Changes valid response code to be in range of 100-399, not 200 only.

Adds option to setup ping request method and interval (in seconds) via
environmental variables, e.g.

  PING_METHOD = 'HEAD' (default) or 'GET'
  PING_INTERVAL = '1200' (default)

Signed-off-by: Aleksandrs Ļedovskis <aleksandrs@ledovskis.lv>
Signed-off-by: Austin Seipp <aseipp@pobox.com>
Acked-by: Austin Seipp <aseipp@pobox.com>
Fixes pinging of root url path.

If PING_URL was set without ending slash the request would fail Solution
- expand '' to '/'

Signed-off-by: Aleksandrs Ļedovskis <aleksandrs@ledovskis.lv>
Signed-off-by: Austin Seipp <aseipp@pobox.com>
Acked-by: Austin Seipp <aseipp@pobox.com>
Modifies README to reflect changes.

Adds paragraph on PING_METHOD and PING_INTERVAL availability.

Signed-off-by: Aleksandrs Ļedovskis <aleksandrs@ledovskis.lv>
Signed-off-by: Austin Seipp <aseipp@pobox.com>
Acked-by: Austin Seipp <aseipp@pobox.com>
Fixes status code checking regxep.

Modifies regexp to allow only numeric values as before fix it would
accept values where first symbol is number and others could be
characters.

Signed-off-by: Aleksandrs Ļedovskis <aleksandrs@ledovskis.lv>
Signed-off-by: Austin Seipp <aseipp@pobox.com>
Acked-by: Austin Seipp <aseipp@pobox.com>
Wibble.

Signed-off-by: Austin Seipp <aseipp@pobox.com>
Remove gemcutter source.

Signed-off-by: Austin Seipp <aseipp@pobox.com>
Update AUTHORS.txt

Signed-off-by: Austin Seipp <aseipp@pobox.com>