add version configuration for each rspec task

jruby-gradle-rspec-plugin/src/main/groovy/com/github/jrubygradle/rspec/RSpec.groovy

@@ -19,11 +19,16 @@ class RSpec extends DefaultTask {
 
     static final String DEFAULT_VERSION = '3.3.0'
   
+    @Input
     String version = DEFAULT_VERSION
 
     @Input
     String jrubyVersion = project.jruby.defaultVersion
 
+    void version(String version) {
+        this.version = version
+    }
+
     void jrubyVersion(String version) {
         this.jrubyVersion = version
     }

jruby-gradle-rspec-plugin/src/test/groovy/com/github/jrubygradle/rspec/JRubyRSpecPluginSpec.groovy

@@ -186,4 +186,43 @@ class JRubyRSpecPluginSpec extends Specification {
         expect:
             output.contains( '2 examples, 0 failures' )
     }
+
+    def "Run custom rspec version"() {
+        given:
+            Files.createSymbolicLink(specDir.toPath(), new File('src/test/resources/rspec-version/spec').getAbsoluteFile().toPath())
+            Task task = project.tasks.getByName('rspec')
+            task.configure {
+                version = '3.2.0'
+            }
+            project.evaluate()
+            String output = captureStdout {
+                task.run()
+            }
+            println output
+        expect:
+            output.contains( '1 example, 0 failures' )
+    }
+
+    def "Run custom rspec version separate from other tasks"() {
+        given:
+            Files.createSymbolicLink(specDir.toPath(), new File('src/test/resources/rspec-version/spec').getAbsoluteFile().toPath())
+            Task task = project.tasks.create('other', RSpec)
+            task.configure {
+                version = '3.2.0'
+            }
+            project.evaluate()
+            String outputOther = captureStdout {
+                task.run()
+            }
+            println outputOther
+            specDir.delete()
+            Files.createSymbolicLink(specDir.toPath(), new File('src/test/resources/simple/spec').getAbsoluteFile().toPath())
+            String output = captureStdout {
+                project.tasks.getByName('rspec').run()
+            }
+            println output
+        expect:
+            outputOther.contains( '1 example, 0 failures' )
+            output.contains( '4 examples, 0 failures' )
+    }
 }

jruby-gradle-rspec-plugin/src/test/resources/rspec-version/spec/one_spec.rb

@@ -0,0 +1,6 @@
+describe 'RSpecVersion' do
+  it 'uses the right rspec version' do
+    require 'rspec'
+    expect(Gem.loaded_specs['rspec'].version.to_s).to eq '3.2.0'
+  end
+end

jruby-gradle-rspec-plugin/src/test/resources/simple/spec/one_spec.rb

@@ -10,4 +10,9 @@ describe 'Simple' do
   it 'has some loaded gems' do
     expect(Gem.loaded_specs.size).to eq 6
   end
+
+  it 'has some loaded gems' do
+    require 'rspec'
+    expect(Gem.loaded_specs['rspec'].version.to_s).not_to eq '3.2.0'
+  end
 end