Sort .gitignore content

Signed-off-by: Arnaud Porterie <arnaud.porterie@docker.com>

.gitignore

@@ -1,33 +1,33 @@
 # Docker project generated files to ignore
 #  if you want to ignore files created by your editor/tools,
 #  please consider a global .gitignore https://help.github.com/articles/ignoring-files
-.vagrant*
-bin
-docker/docker
 *.exe
-.*.swp
-a.out
 *.orig
-build_src
-.flymake*
-.idea
+*.test
+.*.swp
 .DS_Store
+.bashrc
+.dotcloud
+.flymake*
+.git/
+.gopath/
+.hg/
+.idea
+.vagrant*
+Vagrantfile
+a.out
+autogen/
+bin
+build_src
+bundles/
+docker/docker
+docs/AWS_S3_BUCKET
+docs/GITCOMMIT
+docs/GIT_BRANCH
+docs/VERSION
 docs/_build
 docs/_static
 docs/_templates
-.gopath/
-.dotcloud
-*.test
-bundles/
-.hg/
-.git/
-vendor/pkg/
-pyenv
-Vagrantfile
-docs/AWS_S3_BUCKET
-docs/GIT_BRANCH
-docs/VERSION
-docs/GITCOMMIT
 docs/changed-files
-autogen/
-.bashrc
+pyenv
+vendor/pkg/