Bring back vendoring kr/pretty

When we removed kr/pretty, we tried to copy the necessary files into
q. Unfortunately, we didn't copy enough, and q's output was changed.
The amount of code being vendored is trivial, so let's just vendor it.

args.go

@@ -14,6 +14,8 @@ import (
 	"runtime"
 	"strings"
 	"unicode/utf8"
+
+	"github.com/kr/pretty"
 )
 
 // argName returns the source text of the given argument if it's a variable or
@@ -125,7 +127,7 @@ func exprToString(arg ast.Expr) string {
 func formatArgs(args ...interface{}) []string {
 	formatted := make([]string, 0, len(args))
 	for _, a := range args {
-		s := colorize(Sprint(a), cyan)
+		s := colorize(pretty.Sprint(a), cyan)
 		formatted = append(formatted, s)
 	}
 	return formatted

args_test.go

@@ -8,6 +8,8 @@ import (
 	"fmt"
 	"go/ast"
 	"testing"
+
+	"github.com/kr/pretty"
 )
 
 // TestExtractingArgsFromSourceText verifies that exprToString() and argName()
@@ -599,7 +601,7 @@ func TestIsQCall(t *testing.T) {
 			t.Fatalf(
 				"\nTEST %d\nisQCall(%s)\ngot:  %v\nwant: %v",
 				tc.id,
-				Sprint(tc.expr),
+				pretty.Sprint(tc.expr),
 				got,
 				tc.want,
 			)

go.mod

@@ -1 +1,5 @@
 module github.com/y0ssar1an/q
+
+go 1.12
+
+require github.com/kr/pretty v0.1.0

go.sum

@@ -0,0 +1,5 @@
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=