.gitconfig: set color.ui to true

Signed-off-by: Pang Yan Han <pangyanhan@gmail.com>
.bashrc: prepend $HOME/bin to $PATH

Signed-off-by: Pang Yan Han <pangyanhan@gmail.com>
.bashrc: append $HOME/.rvm/bin to $PATH

For use with RVM

Signed-off-by: Pang Yan Han <pangyanhan@gmail.com>
.bashrc: Update yesod-bin directory

Signed-off-by: Pang Yan Han <pangyanhan@gmail.com>
.bashrc: Remove Hakyll sandbox from PATH

Since Hakyll is used as a library and we do not make use of any executables
installed there.

Signed-off-by: Pang Yan Han <pangyanhan@gmail.com>