Update README.textile

Added gem installation options.
Update client.rb comment > Requrs should be Requires
Fix client.rooms to set room's server_url correctly

If try to fetch room's history through fetched rooms object like

    client.rooms.find {|room| room.name =~ /Hipchat/ }.history

fails with

    URI::InvalidURIError: the scheme http does not accept registry part: :80 (or bad hostname?)

This is because `HipChat::Room.base_uri` is not set at `HipChat::Room#initialize`.

This commit fix above issue.
Use rspec ~> 2.0 as development dependency
Merge pull request #93 from yasuoza/fix-rspec-version

Use rspec ~> 2.0 as development dependency
Merge pull request #88 from jufemaiz/master

Update README.textile
Merge pull request #90 from Radagaisus/patch-1

Update client.rb comment > Requrs should be Requires
Merge pull request #92 from yasuoza/fix-room_server_url

Fix client.rooms to set room's server_url correctly
proxy: support ENV['no_proxy']

Normally tools support http(s)_proxy env var as well as the no_proxy env
var which is a comma separated list of glob patterns to match against
the domain of the url.

For example see `man curl` or `man wget`.