Remove local_time gem, and add similar (#2875)

Gemfile.lock

@@ -105,13 +105,6 @@ GEM
     cocaine (0.5.8)
       climate_control (>= 0.0.3, < 1.0)
     coderay (1.1.1)
-    coffee-rails (4.2.1)
-      coffee-script (>= 2.2.0)
-      railties (>= 4.0.0, < 5.2.x)
-    coffee-script (2.4.1)
-      coffee-script-source
-      execjs
-    coffee-script-source (1.12.2)
     colorize (0.8.1)
     concurrent-ruby (1.0.5)
     connection_pool (2.2.1)
@@ -224,8 +217,6 @@ GEM
       letter_opener (~> 1.0)
       railties (>= 3.2)
     link_header (0.0.8)
-    local_time (1.0.3)
-      coffee-rails
     lograge (0.5.0)
       actionpack (>= 4, <= 5.1.0)
       activesupport (>= 4, <= 5.1.0)
@@ -509,7 +500,6 @@ DEPENDENCIES
   letter_opener
   letter_opener_web
   link_header
-  local_time
   lograge
   microformats2
   nokogiri