Directly check if node is installed in bin/configure (#786)

Previously, users who install node with a package manager other than
homebrew would receive a message that the package wasn't installed
via homebrew. Now the code checks whether node is present AND whether
it is the correct version in the same place.

There is a subtle difference in that the previous version would allow
you to continue without installing node but I think this was likely not
intended.

bin/configure

@@ -90,20 +90,18 @@ end
 check_package("postgresql@14")
 check_package("redis")
 check_package("icu4c")
-check_package("node")
-
-if `yarn -v 2> /dev/null`.length > 0
-  puts "Yarn is installed.".green
-else
-  puts "You don't have Yarn installed. We can't proceed without it. Try `brew install yarn` or see the installation instructions at https://yarnpkg.com/getting-started/install .".red
-  exit
-end
-
 
 required_node = `cat ./.nvmrc`.strip
-actual_node = `node -v`.strip.gsub("v", "")
+actual_node = begin
+                `node -v`.strip.gsub("v", "")
+              rescue
+                :not_found
+              end
 message = "Bullet Train requires Node.js #{required_node} and `node -v` returns #{actual_node}."
-if Gem::Version.new(actual_node) >= Gem::Version.new(required_node)
+if actual_node == :not_found
+  puts "You don't have Node installed. We can't proceed without it. Try `brew install node`.".red
+  exit
+elsif Gem::Version.new(actual_node) >= Gem::Version.new(required_node)
   puts message.green
 else
   puts message.red
@@ -113,6 +111,13 @@ else
   end
 end
 
+if `yarn -v 2> /dev/null`.length > 0
+  puts "Yarn is installed.".green
+else
+  puts "You don't have Yarn installed. We can't proceed without it. Try `brew install yarn` or see the installation instructions at https://yarnpkg.com/getting-started/install .".red
+  exit
+end
+
 if File.exist?('.github/workflows/main.yml')
   puts "Removing default GitHub workflow.".yellow
   File.delete('.github/workflows/main.yml')