Update rspec-parameterized to v0.5.0

The new release of the gem allows referencing
"let" variables via 'ref' keyword in parameters.

Gemfile.lock

@@ -9,7 +9,6 @@ GEM
   remote: https://rubygems.org/
   specs:
     RedCloth (4.3.2)
-    abstract_type (0.0.7)
     acme-client (2.0.6)
       faraday (>= 0.17, < 2.0.0)
     actioncable (6.1.3.2)
@@ -76,9 +75,6 @@ GEM
       zeitwerk (~> 2.3)
     acts-as-taggable-on (7.0.0)
       activerecord (>= 5.0, < 6.2)
-    adamantium (0.2.0)
-      ice_nine (~> 0.11.0)
-      memoizable (~> 0.4.0)
     addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
     aes_key_wrap (1.1.0)
@@ -205,9 +201,6 @@ GEM
     colored2 (3.1.2)
     commonmarker (0.21.0)
       ruby-enum (~> 0.5)
-    concord (0.1.5)
-      adamantium (~> 0.2.0)
-      equalizer (~> 0.0.9)
     concurrent-ruby (1.1.9)
     connection_pool (2.2.2)
     contracts (0.11.0)
@@ -336,7 +329,6 @@ GEM
       launchy (~> 2.1)
       mail (~> 2.7)
     encryptor (3.0.0)
-    equalizer (0.0.11)
     erubi (1.9.0)
     escape_utils (1.2.1)
     et-orbi (1.2.1)
@@ -647,7 +639,6 @@ GEM
       concurrent-ruby (~> 1.0)
     i18n_data (0.8.0)
     icalendar (2.4.1)
-    ice_nine (0.11.2)
     invisible_captcha (1.1.0)
       rails (>= 4.2)
     ipaddress (0.8.3)
@@ -748,8 +739,6 @@ GEM
       actionpack (>= 2.3)
       activerecord (>= 2.3)
     memoist (0.16.2)
-    memoizable (0.4.2)
-      thread_safe (~> 0.3, >= 0.3.1)
     memory_profiler (0.9.14)
     method_source (1.0.0)
     mime-types (3.3.1)
@@ -935,7 +924,6 @@ GEM
       coderay
       parser
       unparser
-    procto (0.0.3)
     prometheus-client-mmap (0.12.0)
     pry (0.13.1)
       coderay (~> 1.1)
@@ -1086,7 +1074,7 @@ GEM
     rspec-mocks (3.10.2)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.10.0)
-    rspec-parameterized (0.4.2)
+    rspec-parameterized (0.5.0)
       binding_ninja (>= 0.2.3)
       parser
       proc_to_ast
@@ -1279,7 +1267,6 @@ GEM
       eventmachine (~> 1.0, >= 1.0.4)
       rack (>= 1, < 3)
     thor (1.1.0)
-    thread_safe (0.3.6)
     thrift (0.14.0)
     tilt (2.0.10)
     timecop (0.9.1)
@@ -1332,14 +1319,9 @@ GEM
     uniform_notifier (1.13.0)
     unleash (0.1.5)
       murmurhash3 (~> 0.1.6)
-    unparser (0.4.7)
-      abstract_type (~> 0.0.7)
-      adamantium (~> 0.2.0)
-      concord (~> 0.1.5)
+    unparser (0.6.0)
       diff-lcs (~> 1.3)
-      equalizer (~> 0.0.9)
-      parser (>= 2.6.5)
-      procto (~> 0.0.2)
+      parser (>= 3.0.0)
     uri_template (0.7.0)
     valid_email (0.1.3)
       activemodel

doc/development/testing_guide/best_practices.md

@@ -972,11 +972,16 @@ range of inputs, might look like this:
 describe "#==" do
   using RSpec::Parameterized::TableSyntax
 
+  let(:one) { 1 }
+  let(:two) { 2 }
+
   where(:a, :b, :result) do
     1         | 1         | true
     1         | 2         | false
     true      | true      | true
     true      | false     | false
+    ref(:one) | ref(:one) | true  # let variables must be referenced using `ref`
+    ref(:one) | ref(:two) | false
   end
 
   with_them do