dependency version bump, thanks to Sergey Bushnyak (Sigrlami)
cabal file fixes
travis fixes
travis apt-get-cabal taken from lens package

https://github.com/ekmett/lens/blob/master/travis/cabal-apt-install
travis.yml typo fix
use custom build command
add test dependencies to travis
fixing sdist
fixed warnings in MagickWand/WandImage.hs
fixed warnings in MagickWand/PixelWand.hs
fixed 'toplevel with no type signature' warnings
changed void to come from Control.Monad
removed redundant modules
fixed warnings from MagickCore/Gem.hs
added MonadCatchIO-transformers to build dependencies
fixed redundant module imports for MagickCore/*/Types.hsc
Fixed redundant import for MagickWand/FFI/Types.hsc
removed unused module MagickCore/FFI/MagickCore.hsc
removed line containing MagickCore.hsc
fixed missing toplevel type signature