Update Rails & Sidekiq, version slightly less pessimistically (#319)

Gemfile

@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-gem 'rails', "~> 5.2.6"
+gem 'rails', "~> 5.2"
 gem 'rack-cors', "~> 1.0"
 gem 'pg', "~> 0.20"
 gem 'responders', "~> 3.0"

Gemfile.lock

@@ -74,7 +74,7 @@ GEM
       timers (>= 4.1.1)
     coderay (1.1.2)
     concurrent-ruby (1.1.9)
-    connection_pool (2.2.2)
+    connection_pool (2.2.5)
     crass (1.0.6)
     database_cleaner (1.7.0)
     diff-lcs (1.3)
@@ -178,7 +178,7 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.19.0, < 2.0)
     rake (13.0.6)
-    redis (4.1.0)
+    redis (4.5.1)
     request_store (1.5.1)
       rack (>= 1.4)
     responders (3.0.1)
@@ -201,11 +201,11 @@ GEM
       rspec-mocks (~> 3.7.0)
       rspec-support (~> 3.7.0)
     rspec-support (3.7.0)
-    sidekiq (5.2.5)
+    sidekiq (5.2.10)
       connection_pool (~> 2.2, >= 2.2.2)
-      rack (>= 1.5.0)
+      rack (~> 2.0)
       rack-protection (>= 1.5.0)
-      redis (>= 3.3.5, < 5)
+      redis (~> 4.5, < 4.6.0)
     sidetiq (0.7.2)
       celluloid (>= 0.17.3)
       ice_cube (~> 0.14.0)
@@ -261,7 +261,7 @@ DEPENDENCIES
   pry-rails (~> 0.3)
   puma (~> 5.6)
   rack-cors (~> 1.0)
-  rails (~> 5.2.6)
+  rails (~> 5.2)
   responders (~> 3.0)
   rspec-rails (~> 3.6)
   sidekiq (~> 5.2)