dev: add dockerfile for local dev (#172)

There have been some comments about wanting an easier developer
experience, particularly on MacOS. This adds a Dockerfile which will
create an environment in which all tests can pass and will hopefully
make cross-platform development easier.

Solves #91

Dockerfile

@@ -0,0 +1,20 @@
+FROM debian:latest as builder
+
+ARG BUILDARCH
+RUN apt-get -qq update \
+    && apt-get -qq install -y --no-install-recommends \
+       gcc g++ libfindbin-libs-perl \
+       make cmake libclang-dev git \
+       wget curl gnupg ca-certificates lsb-release \
+    && wget --no-check-certificate -O - https://openresty.org/package/pubkey.gpg | gpg --dearmor -o /usr/share/keyrings/openresty.gpg \
+    && if [ "${BUILDARCH}" = "arm64" ]; then URL="http://openresty.org/package/arm64/debian"; else URL="http://openresty.org/package/debian"; fi \
+    && echo "deb [arch=$BUILDARCH signed-by=/usr/share/keyrings/openresty.gpg] ${URL} $(lsb_release -sc) openresty" | tee /etc/apt/sources.list.d/openresty.list > /dev/null \
+    && apt-get -qq update \
+    && apt-get -qq install -y openresty --no-install-recommends
+
+RUN curl https://sh.rustup.rs -sSf | sh -s -- -y
+ENV PATH="/root/.cargo/bin:${PATH}"
+
+WORKDIR /var/opt/pingora
+COPY . .
+RUN cargo build