Add ability to parse quoted strings in meta

This should actually make migration from Caddy easier, because
Caddy's YAML front matter seems to support quoted strings? IDK,
the current Holanet has them. Closes #11

meta.go

@@ -1,5 +1,6 @@
 package step
 
+import "strconv"
 import "strings"
 
 const metaRule = "---"
@@ -52,6 +53,13 @@ func ParseMeta (input string) (Meta, error) {
 		}
 		key   = strings.ToLower(strings.TrimSpace(key))
 		value = strings.TrimSpace(value)
+		if strings.HasPrefix(value, "\"") || strings.HasPrefix(value, "'") {
+			unquoted, err := strconv.Unquote(value)
+			if err != nil {
+				return nil, err
+			}
+			value = unquoted
+		}
 		if key == "" {
 			return nil, ErrMetaMalformed
 		}

meta_test.go

@@ -85,3 +85,27 @@ func TestSplitMetaCRLF (test *testing.T) {
 	if value3 != "that"        { test.Fatal("value is not correct") }
 	if value4 != quickBrownFox { test.Fatal("value is not correct") }
 }
+
+func TestParseMeta (test *testing.T) {
+	meta, err := ParseMeta(
+`thing: "	Quoted string!!!!!   "
+Other-Thing: askdjlksajd
+
+number: 3849
+`)
+	if err != nil {
+		test.Fatal(err)
+	}
+	
+	test.Log("META:")
+	test.Log(meta)
+	value0, ok := meta["thing"]
+	if !ok { test.Fatal("missing key") }
+	value1, ok := meta["other-thing"]
+	if !ok { test.Fatal("missing key") }
+	value2, ok := meta["number"]
+	if !ok { test.Fatal("missing key") }
+	if value0 != "\tQuoted string!!!!!m   " { test.Fatal("value is not correct") }
+	if value1 != "askdjlksajd"              { test.Fatal("value is not correct") }
+	if value2 != "3849"                     { test.Fatal("value is not correct") }
+}