Update gemspec as per warnings

Author: daveallie

.gitignore

@@ -8,3 +8,4 @@
 /pkg/
 /spec/reports/
 /tmp/
+*.gem

rails_console_commands.gemspec

@@ -12,7 +12,6 @@ Gem::Specification.new do |spec|
   spec.email         = ['[email protected]']
 
   spec.summary       = 'Run rake/rails and test commands through the console'
-  spec.description   = 'Run rake/rails and test commands through the console'
   spec.homepage      = 'https://github.com/TandaHQ/rails_console_commands'
   spec.license       = 'MIT'
 
@@ -25,5 +24,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rake', '~> 10.0'
   spec.add_development_dependency 'rubocop', '~> 0.49'
 
-  spec.add_dependency 'rails', '>= 5'
+  spec.add_dependency 'rails', '~> 5'
 end