Update dependency rspec to v3.13.0 (#449)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Gemfile.lock

@@ -23,7 +23,7 @@ GEM
     byebug (11.1.3)
     concurrent-ruby (1.2.3)
     connection_pool (2.4.1)
-    diff-lcs (1.5.0)
+    diff-lcs (1.5.1)
     docile (1.4.0)
     drb (2.2.0)
       ruby2_keywords
@@ -43,19 +43,19 @@ GEM
     minitest (5.21.2)
     mutex_m (0.2.0)
     rake (13.1.0)
-    rspec (3.12.0)
-      rspec-core (~> 3.12.0)
-      rspec-expectations (~> 3.12.0)
-      rspec-mocks (~> 3.12.0)
-    rspec-core (3.12.2)
-      rspec-support (~> 3.12.0)
-    rspec-expectations (3.12.3)
+    rspec (3.13.0)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.0)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.12.0)
-    rspec-mocks (3.12.6)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.12.0)
-    rspec-support (3.12.1)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.0)
     ruby2_keywords (0.0.5)
     simplecov (0.22.0)
       docile (~> 1.1)