chore(deps): update dependency sprockets to v4.2.2

Author: renovate[bot]

Gemfile.lock

@@ -39,7 +39,7 @@ GEM
       sass (>= 3.3.0, < 3.5)
     compass-import-once (1.0.5)
       sass (>= 3.2, < 3.5)
-    concurrent-ruby (1.2.2)
+    concurrent-ruby (1.2.3)
     console (1.23.6)
       fiber-annotation
       fiber-local
@@ -99,6 +99,7 @@ GEM
     listen (3.8.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
+    logger (1.2.8.1)
     memoist (0.16.2)
     middleman (4.5.0)
       coffee-script (~> 2.2)
@@ -179,7 +180,7 @@ GEM
       ttfunk
     public_suffix (5.0.1)
     racc (1.7.0)
-    rack (2.2.7)
+    rack (2.2.21)
     rack-livereload (0.3.17)
       rack
     rainbow (3.1.1)
@@ -195,8 +196,9 @@ GEM
     sassc (2.4.0)
       ffi (~> 1.9)
     servolux (0.13.0)
-    sprockets (4.2.0)
+    sprockets (4.2.2)
       concurrent-ruby (~> 1.0)
+      logger
       rack (>= 2.2.4, < 4)
     temple (0.10.2)
     thor (1.2.2)