fix: disable colour if stdout redirected

doc/cli/options.txt

@@ -3,7 +3,7 @@ Configuration
   --config <file> .......... alternate nodemon.json config file to use
   --exitcrash .............. exit on crash, allows nodemon to work with other watchers
   -i, --ignore ............. ignore specific files or directories
-  --no-colors .............. disable color output
+  --[no-]color ............. toggle color output
   --signal <signal> ........ use specified kill signal instead of default (ex. SIGTERM)
   -w, --watch dir........... watch directory "dir" or files. use once for each
                              directory or file to watch

lib/cli/parse.js

@@ -175,10 +175,18 @@ function nodemonOption(options, arg, eatNext) {
     options.ext = eatNext();
   } else
 
-  if (arg === '--no-colours' || arg === '--no-colors') {
+  if (arg === '--no-colours' || arg === '--no-colors'
+      || arg === '--no-colour'
+      || arg === '--no-color') {
     options.colours = false;
   } else
 
+  if (arg === '--colours' || arg === '--colors'
+      || arg === '--colour'
+      || arg === '--color') {
+    options.colours = true;
+  } else
+
   if (arg === '--signal' || arg === '-s') {
     options.signal = eatNext();
   } else

lib/config/defaults.js

@@ -3,7 +3,7 @@ var ignoreRoot = require('ignore-by-default').directories();
 // default options for config.options
 module.exports = {
   restartable: 'rs',
-  colours: true,
+  colours: process.stdout.isTTY,
   execMap: {
     py: 'python',
     rb: 'ruby',