Gemfile: remove rake dep supposedly required by travis

Signed-off-by: Alejandro Martinez Ruiz <alex@flawedcode.org>
Merge branch 'remove-rake-from-Gemfile'

* remove-rake-from-Gemfile:
  Gemfile: remove rake dep supposedly required by travis
gemspec: bump to version 1.0.4

Signed-off-by: Alejandro Martinez Ruiz <alex@flawedcode.org>