Latest docker build script for zetaSQL 2020.04.1

# Description

I've been trying to create a parser in the same manner that @apstnb built the format server (https://github.com/apstndb/zetasql-format-server). In particular, I'm interested in using the function `Run` programmatically (and not from the command-line) (It exists inside /experimental/execute_query.cc). In this way, I'd like a docker container that exposes the Run method via a small golang server and I can push a sql statement and get the required AST back.

Has anyone here created a Dockerfile that successfully builds and compiles the latest zetaSQL, similar to https://github.com/apstndb/zetasql-format-server/, but using the latest zetasql (2020.04.1), and not the version in WORKSPACE of the above repo, given below:

```
http_archive(
name = "com_google_zetasql",
strip_prefix = "zetasql-2019.07.1",
urls = [
"https://github.com/google/zetasql/archive/2019.07.1.tar.gz",
],
sha256 = "88871fe511cce67e86321f9eb69cd8f81218a9415f41dff36b066a23b483bf06"
)
```

# The request for help
I've found it quite hard to build the latest zetaSQL using the example in `zetasql-format-server` as a base. Any help with formulating a Dockerfile that successfully exposes an endpoint that takes a SQL and returns an AST of this SQL would be greatly appreciated.