Removed initializer by moving require to encode lib where it belongs.
Refactored encoding of build output.

Moved the GitlabCi::Encode.encode! method call closer to the file read.
This keeps the boundary between "external file source with crazy
encoding -> internal rails code all in utf-8" well defined.
Additionally the build output file is opened in binary mode to prevent
encoding exceptions while reading it. It will be converted to utf-8 by
GitlabCi::Encode.encode!
Merge pull request #100 from cabeca/better-encode

Better encode