feat!: rewrite in Rust

Bump the version to 3.0.0.

All command line functionality should be preserved.  However, this
is not *quite* a refactor because some functionality has changed:

1. The input file argument is optional.  If no input file path is
   given or it is "-", csv2html reads from the standard input.
2. There are more newlines in the output HTML.  I think this
   improves how the output looks.
3. The CSV parser may work differently from Python's.  It does
   not break anything for me and parses my data indentically.
   Please report if it breaks something for you.

Most of the tests remain in Python.

Author: dbohdan

.gitignore

@@ -4,3 +4,5 @@
 *.egg*
 *.pyc
 *.sublime-*
+
+/target/

Cargo.lock

@@ -0,0 +1,11 @@
+[package]
+name = "csv2html"
+version = "3.0.0"
+authors = ["D. Bohdan"]
+edition = "2018"
+
+[dependencies]
+clap = "2.33"
+csv = "1.1"
+exitcode = "1.1.2"
+snafu = "0.6.8"

Cargo.toml

@@ -1,4 +1,4 @@
-Copyright (c) 2013, 2014, 2017 dbohdan.
+Copyright (c) 2013, 2014, 2017, 2020 D. Bohdan.
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,

LICENSE

@@ -0,0 +1,37 @@
+BUILD_USER ?= $(USER)
+USER_TEMP ?= /tmp/$(BUILD_USER)
+PROJECT_TEMP ?= $(USER_TEMP)/csv2html-rust
+TARGET ?= x86_64-unknown-linux-musl
+BUILD_OPTS ?= --target $(TARGET)
+BUILD_OPTS_WITH_DIR ?= $(BUILD_OPTS) --target-dir $(PROJECT_TEMP)
+
+dev: temp-dir
+	# A workaround for https://github.com/rust-lang/rust/issues/46981
+	find Cargo.* src/ tests/ | entr -r sh -c 'cargo check $(BUILD_OPTS_WITH_DIR) < /dev/null'
+
+debug: temp-dir
+	cargo build $(BUILD_OPTS_WITH_DIR)
+
+install:
+	install $(PROJECT_TEMP)/$(TARGET)/release/csv2html /usr/local/bin
+	strip /usr/local/bin/csv2html
+
+release: temp-dir
+	cargo build $(BUILD_OPTS_WITH_DIR) --release
+
+temp-dir:
+	@-mkdir -m 0700 $(USER_TEMP)/ 2> /dev/null
+	@-mkdir $(PROJECT_TEMP)/ 2> /dev/null
+
+test: test-unit test-integration
+
+test-integration: debug
+	CSV2HTML_COMMAND="$(PROJECT_TEMP)/$(TARGET)/debug/csv2html" python3 tests/test_csv2html.py
+
+test-unit:
+	cargo test $(BUILD_OPTS_WITH_DIR)
+
+uninstall:
+	rm /usr/local/bin/csv2html
+
+PHONY: dev install release temp-dir test test-integration test-unit uninstall