Adds support for PostgreSQL which resolves #87 and is mentioned in #246.

This includes migrations as well as Dockerfile's for amd64.

The biggest change is that replace_into isn't supported by Diesel for the
PostgreSQL backend, instead requiring the use of on_conflict. This
unfortunately requires a branch for save() on all of the models currently
using replace_into.

docker/amd64/postgresql/Dockerfile.alpine

@@ -0,0 +1,85 @@
+# Using multistage build: 
+# 	https://docs.docker.com/develop/develop-images/multistage-build/
+# 	https://whitfin.io/speeding-up-rust-docker-builds/
+####################### VAULT BUILD IMAGE  #######################
+FROM alpine:3.10 as vault
+
+ENV VAULT_VERSION "v2.12.0"
+
+ENV URL "https://github.com/dani-garcia/bw_web_builds/releases/download/$VAULT_VERSION/bw_web_$VAULT_VERSION.tar.gz"
+
+RUN apk add --no-cache --upgrade \
+    curl \
+    tar
+
+RUN mkdir /web-vault
+WORKDIR /web-vault
+
+SHELL ["/bin/ash", "-eo", "pipefail", "-c"]
+
+RUN curl -L $URL | tar xz
+RUN ls
+
+########################## BUILD IMAGE  ##########################
+# Musl build image for statically compiled binary
+FROM clux/muslrust:nightly-2019-07-08 as build
+
+# set mysql backend
+ARG DB=postgresql
+
+ENV USER "root"
+
+# Install needed libraries
+RUN apt-get update && apt-get install -y \
+    --no-install-recommends \
+    libpq-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+# Copies the complete project
+# To avoid copying unneeded files, use .dockerignore
+COPY . .
+
+RUN rustup target add x86_64-unknown-linux-musl
+
+# Make sure that we actually build the project
+RUN touch src/main.rs
+
+# Build
+RUN cargo build --features ${DB} --release
+
+######################## RUNTIME IMAGE  ########################
+# Create a new stage with a minimal image
+# because we already have a binary built
+FROM alpine:3.10
+
+ENV ROCKET_ENV "staging"
+ENV ROCKET_PORT=80
+ENV ROCKET_WORKERS=10
+ENV SSL_CERT_DIR=/etc/ssl/certs
+
+# Install needed libraries
+RUN apk add --no-cache \
+        openssl \
+        postgresql-libs \
+        curl \
+        ca-certificates
+
+RUN mkdir /data
+VOLUME /data
+EXPOSE 80
+EXPOSE 3012
+
+# Copies the files from the context (Rocket.toml file and web-vault)
+# and the binary from the "build" stage to the current stage
+COPY Rocket.toml .
+COPY --from=vault /web-vault ./web-vault
+COPY --from=build /app/target/x86_64-unknown-linux-musl/release/bitwarden_rs .
+
+COPY docker/healthcheck.sh ./healthcheck.sh
+
+HEALTHCHECK --interval=30s --timeout=3s CMD sh healthcheck.sh || exit 1
+
+# Configures the startup!
+CMD ["./bitwarden_rs"]