Fixed docker build error

[MohamedKarrab]

When following the instructions to install sneaky gophish,

git clone https://github.com/puzzlepeaches/sneaky_gophish && \
  cd sneaky_gophish && \
  docker build -t sneaky_gophish .

I was getting an error in the docker build command, in this part specifically

RUN apt update && apt install git

Adding the -y after install fixes it.