fix: Gemfile.lock & Gemfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-RUBY-FFI-22037

Gemfile

@@ -25,6 +25,6 @@ group :development do
   gem 'database_cleaner'
   gem 'launchy'
   gem 'pry'
-  gem 'rerun'
+  gem 'rerun', '>= 0.11.0'
   gem 'rake'
 end

Gemfile.lock

@@ -40,7 +40,7 @@ GEM
     dotenv (2.2.1)
     factory_girl (4.8.0)
       activesupport (>= 3.0.0)
-    ffi (1.9.18)
+    ffi (1.9.25)
     i18n (0.8.6)
     jmespath (1.3.1)
     launchy (2.4.3)
@@ -71,10 +71,10 @@ GEM
     rack-test (0.7.0)
       rack (>= 1.0, < 3)
     rake (12.1.0)
-    rb-fsevent (0.10.2)
+    rb-fsevent (0.10.3)
     rb-inotify (0.9.10)
       ffi (>= 0.5.0, < 2)
-    rerun (0.11.0)
+    rerun (0.13.0)
       listen (~> 3.0)
     rspec (3.6.0)
       rspec-core (~> 3.6.0)
@@ -141,7 +141,7 @@ DEPENDENCIES
   poltergeist
   pry
   rake
-  rerun
+  rerun (>= 0.11.0)
   rspec
   sinatra
   sinatra-activerecord
@@ -153,4 +153,4 @@ DEPENDENCIES
   validate_url
 
 BUNDLED WITH
-   1.15.3
+   1.16.1