Throw exception on git failure, rather than exit silently

CHANGELOG.md

@@ -11,6 +11,7 @@ https://github.com/capistrano/capistrano/compare/v3.2.0...HEAD
   * Changed asking question to more standard format (like common unix commandline tools) (@sponomarev)
   * Fixed typos in the README. (@sponomarev)
   * Added `keys` method to Configuration to allow introspection of configuration options. (@juanibiapina)
+  * Improve error message when git:check fails (raise instead of silently `exit 1`) (@mbrictson)
 
 ## `3.2.0`
 

lib/capistrano/git.rb

@@ -18,7 +18,7 @@ class Capistrano::Git < Capistrano::SCM
     end
 
     def check
-      test! :git, :'ls-remote -h', repo_url
+      git :'ls-remote -h', repo_url
     end
 
     def clone

lib/capistrano/tasks/git.rake

@@ -25,7 +25,7 @@ namespace :git do
     fetch(:branch)
     on release_roles :all do
       with fetch(:git_environmental_variables) do
-        exit 1 unless strategy.check
+        strategy.check
       end
     end
   end

spec/lib/capistrano/git_spec.rb

@@ -31,7 +31,7 @@ module Capistrano
     describe "#check" do
       it "should test the repo url" do
         context.expects(:repo_url).returns(:url)
-        context.expects(:test).with(:git, :'ls-remote -h', :url).returns(true)
+        context.expects(:execute).with(:git, :'ls-remote -h', :url).returns(true)
 
         subject.check
       end