Strip whitespace from ansible version

Note: strip! returns nil if there is nothing to be stripped

plugins/provisioners/ansible/provisioner/base.rb

@@ -388,6 +388,7 @@ gathered version stdout version:
             ansible_version_pattern = first_line.match(/(^ansible\s+)(.+)$/)
             if ansible_version_pattern
               _, @gathered_version, _ = ansible_version_pattern.captures
+              @gathered_version.strip!
               if @gathered_version
                 @gathered_version_major = @gathered_version.match(/(\d)\..+$/).captures[0].to_i
               end

test/unit/plugins/provisioners/ansible/provisioner_test.rb

@@ -984,6 +984,16 @@ VF
         end
       end
 
+      describe "whitespace in version string" do
+        before do
+          allow(subject).to receive(:gather_ansible_version).and_return("ansible #{config.version}  \n...\n")
+        end
+
+        it "sets the correct gathered_version" do
+          expect(Vagrant::Util::Subprocess).to receive(:execute).with('ansible-playbook', any_args).and_return(default_execute_result)
+        end
+      end
+
       describe "and there is an ansible version mismatch" do
         before do
           allow(subject).to receive(:gather_ansible_version).and_return("ansible 1.9.6\n...\n")