Clean up first `bin/rake spec:deps` outputclean_rake_spec_deps

Currently the first time you run `bin/rake spec:deps` on a fresh
installation, you get the following output:

```
Could not find 'automatiek' (~> 0.1.0) among 17 total gem(s)
Checked in 'GEM_PATH=/usr/local/rvm/gems/ruby-2.3.7:/usr/local/rvm/gems/ruby-2.3.7@global', execute `gem env` for more information (Gem::MissingSpecError)
Could not find 'mustache' (= 0.99.6) among 17 total gem(s)
Checked in 'GEM_PATH=/usr/local/rvm/gems/ruby-2.3.7:/usr/local/rvm/gems/ruby-2.3.7@global', execute `gem env` for more information (Gem::MissingSpecError)
Could not find 'rake' (~> 12.0) - did find: [rake-10.4.2]
Checked in 'GEM_PATH=/usr/local/rvm/gems/ruby-2.3.7:/usr/local/rvm/gems/ruby-2.3.7@global', execute `gem env` for more information (Gem::MissingSpecVersionError)
Could not find 'rdiscount' (~> 2.2) among 17 total gem(s)
Checked in 'GEM_PATH=/usr/local/rvm/gems/ruby-2.3.7:/usr/local/rvm/gems/ruby-2.3.7@global', execute `gem env` for more information (Gem::MissingSpecError)
Could not find 'ronn' (~> 0.7.3) among 17 total gem(s)
Checked in 'GEM_PATH=/usr/local/rvm/gems/ruby-2.3.7:/usr/local/rvm/gems/ruby-2.3.7@global', execute `gem env` for more information (Gem::MissingSpecError)
Could not find 'rspec' (~> 3.6) among 17 total gem(s)
Checked in 'GEM_PATH=/usr/local/rvm/gems/ruby-2.3.7:/usr/local/rvm/gems/ruby-2.3.7@global', execute `gem env` for more information (Gem::MissingSpecError)
Could not find 'rubocop' (= 0.50.0) among 17 total gem(s)
Checked in 'GEM_PATH=/usr/local/rvm/gems/ruby-2.3.7:/usr/local/rvm/gems/ruby-2.3.7@global', execute `gem env` for more information (Gem::MissingSpecError)
```

Nothing has gone wrong but the user might think the opposite. So, avoid
printing these errors.

1 files changed, 10 insertions, 8 deletions

diff --git a/bin/rake b/bin/rake
index ebb192fd50..7cce4cfa1e 100755
--- a/bin/rake
+++ b/bin/rake
@@ -5,15 +5,17 @@ load File.expand_path("../with_rubygems", __FILE__) if ENV["RGV"]
 
 require "rubygems"
 
-bundler_spec = Gem::Specification.load(File.expand_path("../../bundler.gemspec", __FILE__))
-bundler_spec.dependencies.each do |dep|
-  begin
-    gem dep.name, dep.requirement
-  rescue Gem::LoadError => e
-    $stderr.puts "#{e.message} (#{e.class})"
+unless ARGV[0] == "spec:deps"
+  bundler_spec = Gem::Specification.load(File.expand_path("../../bundler.gemspec", __FILE__))
+  bundler_spec.dependencies.each do |dep|
+    begin
+      gem dep.name, dep.requirement
+    rescue Gem::LoadError => e
+      $stderr.puts "#{e.message} (#{e.class})"
+    end
   end
-end
 
-Gem.finish_resolve if Gem.respond_to?(:finish_resolve)
+  Gem.finish_resolve if Gem.respond_to?(:finish_resolve)
+end
 
 load Gem.bin_path("rake", "rake")