Upgrade hcl to v2

Signed-off-by: Patrick Van Stee <patrick@vanstee.me>

vendor/github.com/zclconf/go-cty/cty/error.go

@@ -0,0 +1,55 @@
+package cty
+
+import (
+	"fmt"
+)
+
+// PathError is a specialization of error that represents where in a
+// potentially-deep data structure an error occured, using a Path.
+type PathError struct {
+	error
+	Path Path
+}
+
+func errorf(path Path, f string, args ...interface{}) error {
+	// We need to copy the Path because often our caller builds it by
+	// continually mutating the same underlying buffer.
+	sPath := make(Path, len(path))
+	copy(sPath, path)
+	return PathError{
+		error: fmt.Errorf(f, args...),
+		Path:  sPath,
+	}
+}
+
+// NewErrorf creates a new PathError for the current path by passing the
+// given format and arguments to fmt.Errorf and then wrapping the result
+// similarly to NewError.
+func (p Path) NewErrorf(f string, args ...interface{}) error {
+	return errorf(p, f, args...)
+}
+
+// NewError creates a new PathError for the current path, wrapping the given
+// error.
+func (p Path) NewError(err error) error {
+	// if we're being asked to wrap an existing PathError then our new
+	// PathError will be the concatenation of the two paths, ensuring
+	// that we still get a single flat PathError that's thus easier for
+	// callers to deal with.
+	perr, wrappingPath := err.(PathError)
+	pathLen := len(p)
+	if wrappingPath {
+		pathLen = pathLen + len(perr.Path)
+	}
+
+	sPath := make(Path, pathLen)
+	copy(sPath, p)
+	if wrappingPath {
+		copy(sPath[len(p):], perr.Path)
+	}
+
+	return PathError{
+		error: err,
+		Path:  sPath,
+	}
+}