Capistrano or Rails Error

gistfile1.txt

rails server        
/Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/rake-12.3.0/lib/rake/task_manager.rb:59:in `[]': Don't know how to build task 'deploy' (see --tasks) (RuntimeError)
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/rake-12.3.0/lib/rake/task.rb:362:in `[]'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/capistrano-3.10.0/lib/capistrano/dsl/task_enhancements.rb:7:in `before'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/bundler/gems/capistrano-gitflow-41dc0f522e0c/lib/capistrano/gitflow/helpers/helper.rb:16:in `gitflow_callbacks'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/bundler/gems/capistrano-gitflow-41dc0f522e0c/lib/capistrano/tasks/gitflow.rb:32:in `block in <top (required)>'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/rake-12.3.0/lib/rake/task_manager.rb:220:in `in_namespace'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/rake-12.3.0/lib/rake/dsl_definition.rb:141:in `namespace'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/bundler/gems/capistrano-gitflow-41dc0f522e0c/lib/capistrano/tasks/gitflow.rb:2:in `<top (required)>'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/activesupport-5.1.2/lib/active_support/dependencies.rb:292:in `require'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/activesupport-5.1.2/lib/active_support/dependencies.rb:292:in `block in require'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/activesupport-5.1.2/lib/active_support/dependencies.rb:258:in `load_dependency'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/activesupport-5.1.2/lib/active_support/dependencies.rb:292:in `require'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/bundler/gems/capistrano-gitflow-41dc0f522e0c/lib/capistrano/gitflow.rb:12:in `<top (required)>'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/bundler-1.16.0.pre.3/lib/bundler/runtime.rb:97:in `require'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/bundler-1.16.0.pre.3/lib/bundler/runtime.rb:97:in `rescue in block in require'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/bundler-1.16.0.pre.3/lib/bundler/runtime.rb:74:in `block in require'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/bundler-1.16.0.pre.3/lib/bundler/runtime.rb:67:in `each'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/bundler-1.16.0.pre.3/lib/bundler/runtime.rb:67:in `require'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/bundler-1.16.0.pre.3/lib/bundler.rb:114:in `require'
	from /Users/KamalIqlaas/Desktop/name/name-web/config/application.rb:5:in `<top (required)>'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/railties-5.1.2/lib/rails/commands/server/server_command.rb:129:in `require'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/railties-5.1.2/lib/rails/commands/server/server_command.rb:129:in `block in perform'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/railties-5.1.2/lib/rails/commands/server/server_command.rb:126:in `tap'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/railties-5.1.2/lib/rails/commands/server/server_command.rb:126:in `perform'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/thor-0.19.4/lib/thor/command.rb:27:in `run'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/thor-0.19.4/lib/thor/invocation.rb:126:in `invoke_command'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/thor-0.19.4/lib/thor.rb:369:in `dispatch'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/railties-5.1.2/lib/rails/command/base.rb:63:in `perform'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/railties-5.1.2/lib/rails/command.rb:44:in `invoke'
	from /Users/KamalIqlaas/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/railties-5.1.2/lib/rails/commands.rb:16:in `<top (required)>'
	from bin/rails:8:in `require'
	from bin/rails:8:in `<main>'