feat(setup): add webpacker gem only when needed

Gemfile

@@ -14,4 +14,3 @@ gemspec
 # gem "debugger"
 gem "activeadmin"
 gem "devise"
-gem "webpacker", "~> 5.0"

Gemfile.lock

@@ -204,8 +204,6 @@ GEM
     puma (4.3.5)
       nio4r (~> 2.0)
     rack (2.2.2)
-    rack-proxy (0.6.5)
-      rack
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
     rails (5.2.4.1)
@@ -290,7 +288,6 @@ GEM
     selenium-webdriver (3.142.7)
       childprocess (>= 0.5, < 4.0)
       rubyzip (>= 1.2.2)
-    semantic_range (2.3.0)
     shellany (0.0.1)
     shoulda-matchers (4.2.0)
       activesupport (>= 4.2.0)
@@ -316,11 +313,6 @@ GEM
       nokogiri (~> 1.6)
       rubyzip (>= 1.3.0)
       selenium-webdriver (>= 3.0, < 4.0)
-    webpacker (5.2.1)
-      activesupport (>= 5.2)
-      rack-proxy (>= 0.6.1)
-      railties (>= 5.2)
-      semantic_range (>= 2.3.0)
     websocket-driver (0.7.1)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.4)
@@ -353,7 +345,6 @@ DEPENDENCIES
   shoulda-matchers
   sqlite3
   webdrivers
-  webpacker (~> 5.0)
 
 BUNDLED WITH
    1.17.2

bin/setup

@@ -17,11 +17,14 @@ cd spec/dummy
 git checkout .
 git clean -f -d
 rake db:setup
+bundle config frozen false
 if [ "$1" = "--use_webpacker" ]; then
+  bundle add webpacker  --version "~>5.0"
   bundle exec rails webpacker:install
   bundle exec rails generate active_admin:install --skip-users --skip-comments --use_webpacker
 else
   set +e
+  bundle remove webpacker
   yarn remove @activeadmin/activeadmin @rails/webpacker activeadmin_addons webpack-dev-server
   set -e
   bundle exec rails generate active_admin:install --skip-users --skip-comments