Conform to PEP8

Though [it is generally recommended to have a trailing
newline](https://stackoverflow.com/questions/2287967/why-is-it-recommended-to-have-empty-line-in-the-end-of-file)

dotdrop/dotfile.py

@@ -41,4 +41,3 @@ class Dotfile:
 
     def __hash__(self):
         return hash(self.dst) ^ hash(self.src) ^ hash(self.key)
-

dotdrop/installer.py

@@ -94,8 +94,11 @@ class Installer:
             os.makedirs(dst)
 
         if os.path.isfile(dst):
-            msg = 'Remove regular file "{}" and replace with empty directory?' \
-                .format(dst)
+            msg = ''.join([
+                'Remove regular file "{}" and ',
+                'replace with empty directory?',
+            ]).format(dst)
+
             if self.safe and not self.log.ask(msg):
                 msg = 'ignoring "{}", nothing installed'
                 self.log.warn(msg.format(dst))
@@ -344,4 +347,3 @@ class Installer:
         self.comparing = False
         self.create = createsaved
         return ret, tmpdst
-

dotdrop/linktypes.py

@@ -5,4 +5,3 @@ class LinkTypes(IntEnum):
     NOLINK = 0
     PARENTS = 1
     CHILDREN = 2
-

dotdrop/utils.py

@@ -115,4 +115,3 @@ def strip_home(path):
 def flatten(a):
     """flatten list"""
     return functools.reduce(operator.iconcat, a, [])
-