Dockerize the application

Dockerfile

@@ -0,0 +1,20 @@
+# Build the application
+FROM golang:1.15-alpine AS build
+RUN apk update && apk upgrade && \
+    apk add --no-cache bash git openssh
+WORKDIR /app
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+RUN go build \
+        -o pasty \
+        -ldflags "\
+            -X github.com/Lukaesebrot/pasty/internal/static.Version=$(git rev-parse --abbrev-ref HEAD)-$(git describe --tags --abbrev=0)-$(git log --pretty=format:'%h' -n 1)" \
+        ./cmd/pasty/main.go
+
+# Run the application in an empty alpine environment
+FROM alpine:latest
+WORKDIR /root
+COPY --from=build /app/pasty .
+COPY web ./web/
+CMD ["./pasty"]