update powerline config files

Signed-off-by: Wang Zhen <yuchen12@gmail.com>
change command-t to ctrlp

Signed-off-by: Wang Zhen <yuchen12@gmail.com>
update vimrc

Signed-off-by: Wang Zhen <yuchen12@gmail.com>
change powerline to airline

Signed-off-by: Wang Zhen <yuchen12@gmail.com>