[fix] Fixed Dockerfile

Dockerfile

@@ -2,16 +2,18 @@
 # docker build -t lazygit .
 # docker run -it lazygit:latest /bin/sh
 
-FROM golang:1.14-alpine3.11
+FROM golang:1.18 as build 
 WORKDIR /go/src/github.com/jesseduffield/lazygit/
-COPY ./ .
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
 RUN CGO_ENABLED=0 GOOS=linux go build
 
-FROM alpine:3.11
-RUN apk add -U git xdg-utils
+FROM alpine:3.15
+RUN apk add --no-cache -U git xdg-utils
 WORKDIR /go/src/github.com/jesseduffield/lazygit/
-COPY --from=0 /go/src/github.com/jesseduffield/lazygit /go/src/github.com/jesseduffield/lazygit
-COPY --from=0 /go/src/github.com/jesseduffield/lazygit/lazygit /bin/
+COPY --from=build /go/src/github.com/jesseduffield/lazygit ./
+COPY --from=build /go/src/github.com/jesseduffield/lazygit/lazygit /bin/
 RUN echo "alias gg=lazygit" >> ~/.profile
 
 ENTRYPOINT [ "lazygit" ]