Add pre-commit hooks with some basic linting

Mostly to keep an eye on code quality as I move forward.

.pre-commit-config.yaml

@@ -0,0 +1,15 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v2.4.0
+    hooks:
+      - id: trailing-whitespace
+        args: [--markdown-linebreak-ext=md]
+      - id: end-of-file-fixer
+      - id: check-toml
+      - id: check-added-large-files
+      - id: debug-statements
+  - repo: https://gitlab.com/pycqa/flake8
+    rev: "master" # pick a git hash / tag to point to
+    hooks:
+      - id: flake8
+        additional_dependencies: [flake8-import-order, flake8-bugbear]

.travis.yml

@@ -69,4 +69,4 @@
     "make -e $BUILD"
   ],
   "sudo": true
-}
+}

Makefile

@@ -83,7 +83,7 @@ install-test: install-servers install-dev
 
 install-style: install-docs install-dev
 	pip install -U flake8 flake8-import-order flake8-bugbear autopep8
-	
+
 style:
 	flake8
 	! git grep -i syncroniz */*

docs/changelog.rst

@@ -1 +1 @@
-.. include:: ../CHANGELOG.rst 
+.. include:: ../CHANGELOG.rst

docs/config.rst

@@ -286,7 +286,7 @@ Service to hardcode those into opensource software [googleterms]_:
 
 3. In the sidebar, select "Credentials" and create a new "OAuth Client ID". The
    application type is "Other".
-   
+
    You'll be prompted to create a OAuth consent screen first. Fill out that
    form however you like.
 
@@ -368,7 +368,7 @@ password. Neither are stored.
         secrets_dir = ...
         #server_path = ...
         #db_path = ...
-   
+
    :param email: The email address of your account.
    :param secrets_dir: A directory where vdirsyncer can store the encryption
                        key and authentication token.
@@ -386,7 +386,7 @@ password. Neither are stored.
         secrets_dir = ...
         #server_path = ...
         #db_path = ...
-   
+
     :param email: The email address of your account.
     :param secrets_dir: A directory where vdirsyncer can store the encryption
                         key and authentication token.

docs/keyring.rst

@@ -60,7 +60,7 @@ passwords from the OS's password store. Installation::
 Basic usage::
 
     password.fetch = ["command", "keyring", "get", "example.com", "foouser"]
-    
+
 .. _keyring: https://github.com/jaraco/keyring/
 
 Password Prompt

docs/tutorials/claws-mail.rst

@@ -77,7 +77,7 @@ Then search for the for the vCard in the folder **~/.contacts/**. Click
 ok, and you we will see your contacts.
 
 .. note::
-    
+
     Claws-Mail shows only contacts that have a mail address.
 
 Crontab

docs/when.rst

@@ -39,7 +39,7 @@ program chosen:
 * Like with ``todo.txt``, Dropbox and friends are obviously agnostic/unaware of
   the files' contents. If a file has changed on both sides, Dropbox just copies
   both versions to both sides.
-  
+
   This is a good idea if the user is directly interfacing with the file system
   and is able to resolve conflicts themselves.  Here it might lead to
   erroneous behavior with e.g. ``khal``, since there are now two events with

scripts/dpkg.Dockerfile

@@ -9,7 +9,7 @@ ARG distrover
 RUN apt-get update
 RUN apt-get install -y build-essential fakeroot debhelper git
 RUN apt-get install -y python3-all python3-pip
-RUN apt-get install -y ruby ruby-dev 
+RUN apt-get install -y ruby ruby-dev
 RUN apt-get install -y python-all python-pip
 
 RUN gem install fpm