New gulp build script (Issue #107)

gulpfile.js

@@ -0,0 +1,15 @@
+var gulp       = require('gulp'),
+    concat     = require('gulp-concat'),
+    sourcemaps = require('gulp-sourcemaps'),
+    ignore     = require('gulp-ignore'),
+    uglify     = require('gulp-uglify');
+
+gulp.task('build', function () {
+    gulp.src(['libs/*', 'dist/pptxgen.js'])
+        .pipe(concat('pptxgen.bundle.js'))
+        .pipe(sourcemaps.init())
+        .pipe(ignore.exclude(["**/*.map"]))
+        .pipe(uglify())
+        .pipe(sourcemaps.write('./'))
+        .pipe(gulp.dest('dist/'));
+});