Task: Simplify development

The base directory has all shell scripts in scripts/
and all example/test files in examples/.
A Makefile provides all the commands with helpful information.
If a developer simply types `make` then vendor is properly updated,
the code is formatted, linted, tested, built, acceptance test run,
and installed.

Linting errors resolved.
Ignored test case (`TestParsePath`) updated to work as expected.

scripts/acceptance.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+set -e
+
+# acceptance test
+X=$(./bin/yaml w ./examples/sample.yaml b.c 3 | ./bin/yaml r - b.c)
+
+if [ $X != 3 ]
+  then
+  echo "Failed acceptance test: expected 2 but was $X"
+  exit 1
+fi