Only use precommit and prepush hooks when working on develop branch.

This should solve @iconexperience's troubles outlined in https://github.com/paperjs/paper.js/issues/1116#issuecomment-244037792

.travis.yml

@@ -32,7 +32,7 @@ install:
 before_script:
 - travis/setup-git.sh
 - npm set progress=false
-- which gulp || npm install -g gulp
+- which gulp || npm install -g gulp-cli
 - npm install
 script:
 - gulp jshint

gulp/utils/options.js

@@ -13,7 +13,8 @@
 var execSync = require('child_process').execSync,
     // Require the __options object, so we have access to the version number and
     // make amendments, e.g. the release date.
-    options = require('../../src/options.js');
+    options = require('../../src/options.js'),
+    argv = require('minimist')(process.argv.slice(2));
 
 function git(command) {
     return execSync('git ' + command).toString().trim();
@@ -22,6 +23,13 @@ function git(command) {
 options.date = git('log -1 --pretty=format:%ad');
 options.branch = git('rev-parse --abbrev-ref HEAD');
 
+// If a specific branch is requested, quit without errors if we don't match.
+if (argv.branch && argv.branch !== options.branch) {
+    console.log('Branch "' + options.branch + '" does not match "' +
+            argv.branch + '". There is nothing to do here.');
+    process.exit(0);
+}
+
 // Get the date of the last commit from this branch for release date:
 var version = options.version,
     branch = options.branch;

package.json

@@ -15,8 +15,8 @@
   ],
   "main": "dist/paper-full.js",
   "scripts": {
-    "precommit": "gulp jshint",
-    "prepush": "gulp test",
+    "precommit": "gulp jshint --branch develop",
+    "prepush": "gulp test --branch develop",
     "build": "gulp build",
     "dist": "gulp dist",
     "zip": "gulp zip",
@@ -66,6 +66,7 @@
     "jshint": "^2.9.2",
     "jshint-summary": "^0.4.0",
     "merge-stream": "^1.0.0",
+    "minimist": "^1.2.0",
     "prepro": "^2.4.0",
     "qunitjs": "^1.23.0",
     "require-dir": "^0.3.0",