Require all in steam-condenser

This must be included, because now showing `uninitialized constant SteamCondenser::Servers` when requiring only `steam-condenser`.
Move requires to steam-condenser

Remove all.rb from steam-condenser
Add coverage/ to .gitignore
Merge branch 'jpalumickas-patch-1'
Update multi_json dependency to 1.8.0
Update rake dependency to 10.1.0
Update mocha dependency to 0.14.0
Require Ruby >= 1.9.2 in gemspec