Update dependencies due to vulnerabilities.

Gemfile.lock

@@ -100,7 +100,7 @@ GEM
     coffee-script-source (1.12.2)
     concurrent-ruby (1.0.5)
     connection_pool (2.2.0)
-    crass (1.0.3)
+    crass (1.0.4)
     debug_inspector (0.0.2)
     devise (4.2.0)
       bcrypt (~> 3.0)
@@ -156,7 +156,7 @@ GEM
     kaminari (0.16.3)
       actionpack (>= 3.0.0)
       activesupport (>= 3.0.0)
-    loofah (2.1.1)
+    loofah (2.2.2)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.0)
@@ -170,7 +170,7 @@ GEM
     net-scp (1.2.1)
       net-ssh (>= 2.6.5)
     net-ssh (3.2.0)
-    nokogiri (1.8.1)
+    nokogiri (1.8.2)
       mini_portile2 (~> 2.3.0)
     oj (3.3.10)
     opentracing (0.3.2)
@@ -195,8 +195,8 @@ GEM
       method_source (~> 0.8.1)
       slop (~> 3.4)
     puma (2.15.3)
-    rack (1.6.8)
-    rack-protection (1.5.3)
+    rack (1.6.10)
+    rack-protection (1.5.5)
       rack
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -217,8 +217,8 @@ GEM
       activesupport (>= 4.2.0, < 5.0)
       nokogiri (~> 1.6)
       rails-deprecated_sanitizer (>= 1.0.1)
-    rails-html-sanitizer (1.0.3)
-      loofah (~> 2.0)
+    rails-html-sanitizer (1.0.4)
+      loofah (~> 2.2, >= 2.2.2)
     railties (4.2.7.1)
       actionpack (= 4.2.7.1)
       activesupport (= 4.2.7.1)