Pipfile syntax invalid when installing editable requirements with extras_require flag.
For given command:
```bash
pipenv install  "git+https://github.com/requests/requests.git@master#egg=requests[security]"
```
that executes successfully, the produced Pipfile is unfortunately not valid.

```toml
[[source]]
url = "https://pypi.python.org/simple"
verify_ssl = true

[packages."requests[security]"]
git = "https://github.com/requests/requests.git"
ref = "master"
```
diff --git a/pipenv/utils.py b/pipenv/utils.py
index d2828e69..f6b7ed24 100644
--- a/pipenv/utils.py
+++ b/pipenv/utils.py
@@ -162,8 +162,11 @@ def convert_deps_from_pip(dep):
                              'dependencies. Please install remote dependency '
                              'in the form {0}#egg=<package-name>.'.format(req.uri))
 
+        # Extras: e.g. #egg=requests[security]
+        if req.extras:
+            dependency[req.name] = {'extras': req.extras}
         # Crop off the git+, etc part.
-        dependency[req.name] = {req.vcs: req.uri[len(req.vcs) + 1:]}
+        dependency.setdefault(req.name, {}).update({req.vcs: req.uri[len(req.vcs) + 1:]})
 
         # Add --editable, if it's there.
         if req.editable:
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 49e0a021..29d26e5d 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -103,6 +103,13 @@ class TestUtils:
         dep = pipenv.utils.convert_deps_from_pip(dep)
         assert dep == {'MyProject': {'hg': 'http://hg.myproject.org/MyProject', 'ref': 'da39a3ee5e6b'}}
 
+        # vcs dependency with extras_require
+        dep = 'git+https://github.com/requests/requests.git@master#egg=requests[security]'
+        dep = pipenv.utils.convert_deps_from_pip(dep)
+        assert dep == {'requests': {'git': 'https://github.com/requests/requests.git',
+                                    'ref': 'master',
+                                    'extras': ['security']}}
+
         # vcs dependency without #egg
         dep = 'git+https://github.com/kennethreitz/requests.git'
         with pytest.raises(ValueError) as e:
['pipenv/utils.py', 'tests/test_utils.py']