include type declarations in dist (#102)

Author: bjon

gulpfile.js

@@ -23,6 +23,7 @@ var buffer = require('vinyl-buffer');
 var source = require('vinyl-source-stream');
 
 var SRC_FILE = 'stackdriver-errors.js';
+var TYPINGS_FILE = 'stackdriver-errors.d.ts';
 var DEST = 'dist/';
 
 var polyfills = [
@@ -52,7 +53,9 @@ gulp.task('lib-concat', function() {
     .pipe(uglify())
     .pipe(rename({extname: '.min.js'}))
     .pipe(sourcemaps.write('maps'))
-    .pipe(gulp.dest(DEST));
+    .pipe(gulp.dest(DEST))
+    .pipe(gulp.src(TYPINGS_FILE))
+    .pipe(gulp.dest(DEST));  
 });
 
 gulp.task('demo-html', function() {