Remove unused app/constants/ dir

All the constants are defined here:
https://github.com/openbmc/phosphor-webui/blob/master/app/common/services/constants.js
Constants are injected as part of app.common.services.
This environment-constants.js or environment-constants.json could
be repurposed to configure features but going with something else,
https://gerrit.openbmc-project.xyz/#/c/11311/.

Tested: Quick manual regression test on the pages.
Change-Id: I59ba4f47fe8a927cb5f68a2657dfea9c61cd5f28
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/gulp_tasks/webapp.js b/gulp_tasks/webapp.js
index edeaff8..f26f169 100644
--- a/gulp_tasks/webapp.js
+++ b/gulp_tasks/webapp.js
@@ -62,13 +62,6 @@
       .pipe(gulp.dest(options.tempFolderPath + '/styles'));
 });
 
-gulp.task('webapp:constants', function() {
-  return gulp.src('environment-constants.json')
-      .pipe(ngConstant({'name': 'app.constants', 'deps': false}))
-      .pipe(rename('environment-constants.js'))
-      .pipe(gulp.dest(options.tempFolderPath + '/constants'));
-});
-
 // ----- To target/webapp from .temp and bower_components
 gulp.task('webapp:template', function() {
   return gulp
@@ -108,6 +101,6 @@
   return runSequence(
       'webapp:clean', 'webapp:sasscompile',
       ['webapp:copyjs', 'webapp:copycss', 'webapp:copyothers'],
-      ['webapp:constants', 'webapp:template'], ['webapp:useref'],
-      ['webapp:copyresources'], callback);
+      ['webapp:template'], ['webapp:useref'], ['webapp:copyresources'],
+      callback);
 };