diff --git a/Dockerfile b/Dockerfile
index 52e72de..fb8c4cb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -6,4 +6,5 @@ RUN mkdir -p lib/sql_enum gemfiles
 COPY lib/sql_enum/version.rb  ./lib/sql_enum/
 COPY gemfiles/*.gemfile gemfiles/
 COPY sql_enum.gemspec Gemfile Gemfile.lock Appraisals ./
-RUN bundle install && exec appraisal install
+RUN bundle install && \
+    bundle exec appraisal install
diff --git a/Gemfile b/Gemfile
index 21eeb1a..599a997 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
-git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
+git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
 # Specify your gem's dependencies in sql_enum.gemspec
 gemspec
diff --git a/docker-compose.yml b/docker-compose.yml
index 1e46404..a6f2310 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,3 +1,5 @@
+---
+
 services:
   rspec:
     build: .
@@ -18,6 +20,6 @@ services:
       - MYSQL_USER
       - MYSQL_PASSWORD
     healthcheck:
-      test: ["CMD", "mysqladmin" ,"ping", "-h", "localhost"]
+      test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]
       timeout: 20s
       retries: 10
diff --git a/gemfiles/rails_5.1.gemfile b/gemfiles/rails_5.1.gemfile
deleted file mode 100644
index 6100e83..0000000
--- a/gemfiles/rails_5.1.gemfile
+++ /dev/null
@@ -1,7 +0,0 @@
-# This file was generated by Appraisal
-
-source "https://rubygems.org"
-
-gem "rails", "~> 5.1.0"
-
-gemspec path: "../"
diff --git a/gemfiles/rails_5.2.gemfile b/gemfiles/rails_5.2.gemfile
deleted file mode 100644
index 5a706dc..0000000
--- a/gemfiles/rails_5.2.gemfile
+++ /dev/null
@@ -1,7 +0,0 @@
-# This file was generated by Appraisal
-
-source "https://rubygems.org"
-
-gem "rails", "~> 5.2.0"
-
-gemspec path: "../"
diff --git a/gemfiles/rails_7.0.gemfile b/gemfiles/rails_7.0.gemfile
deleted file mode 100644
index 9af0ae3..0000000
--- a/gemfiles/rails_7.0.gemfile
+++ /dev/null
@@ -1,7 +0,0 @@
-# This file was generated by Appraisal
-
-source "https://rubygems.org"
-
-gem "rails", "~> 7.0.0"
-
-gemspec path: "../"