diff --git a/pipenv/requirements.py b/pipenv/requirements.py
index 45fa403d..5a998d0c 100644
--- a/pipenv/requirements.py
+++ b/pipenv/requirements.py
@@ -52,7 +52,9 @@ def _validate_specifiers(instance, attr_, value):
     except InvalidMarker:
         raise ValueError('Invalid Specifiers {0}'.format(value))
 
-_optional_instance_of = lambda cls: validators.optional(validators.instance_of(cls))
+
+def _optional_instance_of(cls):
+    return validators.optional(validators.instance_of(cls))
 
 
 @attrs
@@ -516,7 +518,6 @@ class PipenvRequirement(object):
             line = line.split(' ', 1)[1]
         line, markers = cls._split_markers(line)
         line, extras = _strip_extras(line)
-        req_dict = defaultdict(None)
         vcs = None
         if is_installable_file(line):
             req_dict = cls._prep_path(line)
@@ -785,8 +786,10 @@ def _extras_to_string(extras):
 
 
 def build_vcs_link(
-    vcs, uri, name=None, ref=None, subdirectory=None, extras= []
+    vcs, uri, name=None, ref=None, subdirectory=None, extras=None
 ):
+    if extras is None:
+        extras = []
     vcs_start = '{0}+'.format(vcs)
     if not uri.startswith(vcs_start):
         uri = '{0}{1}'.format(vcs_start, uri)
diff --git a/pipenv/utils.py b/pipenv/utils.py
index 3ab9b945..d3802703 100644
--- a/pipenv/utils.py
+++ b/pipenv/utils.py
@@ -60,7 +60,7 @@ if six.PY2:
 specifiers = [k for k in lookup.keys()]
 # List of version control systems we support.
 VCS_LIST = ('git', 'svn', 'hg', 'bzr')
-SCHEME_LIST = ('http://', 'https://', 'ftp://', 'file://')
+SCHEME_LIST = ('http://', 'https://', 'ftp://', 'ftps://', 'file://')
 requests = requests.Session()
 
 
@@ -442,7 +442,6 @@ def multi_split(s, split):
 def convert_deps_from_pip(dep):
     """"Converts a pip-formatted dependency to a Pipfile-formatted one."""
     from .requirements import PipenvRequirement
-    dependency = {}
     req = PipenvRequirement.from_line(dep)
     return req.as_pipfile()
 
@@ -1001,7 +1000,7 @@ class TemporaryDirectory(object):
             import uuid
 
             name = uuid.uuid4().hex
-            dir_name = os.path.sep.join([os.environ['RAM_DISK'].strip(), name])
+            dir_name = os.path.join(os.environ['RAM_DISK'].strip(), name)
             os.mkdir(dir_name)
             self.name = dir_name
         else:
diff --git a/tests/test_pipenv.py b/tests/test_pipenv.py
index f1e87973..cede5455 100644
--- a/tests/test_pipenv.py
+++ b/tests/test_pipenv.py
@@ -1084,16 +1084,13 @@ requests = "==2.14.0"
         with PipenvInstance(pypi=pypi) as p:
 
             c = p.pipenv('install https://github.com/divio/django-cms/archive/release/3.4.x.zip')
-            key = [k for k in p.pipfile['packages'].keys()][0]
-            dep = p.pipfile['packages'][key]
-
-            assert 'file' in dep
             assert c.return_code == 0
 
-            key = [k for k in p.lockfile['default'].keys()][0]
-            dep = p.lockfile['default'][key]
+            dep = list(p.pipfile['packages'].values())[0]
+            assert 'file' in dep, p.pipfile
 
-            assert 'file' in dep
+            dep = list(p.lockfile['default'].values())[0]
+            assert 'file' in dep, p.lockfile
 
     @pytest.mark.install
     @pytest.mark.files