Major dependency update (#1974)

* [V3] Stop `tmp` dir showing up

* [V3] Remove requirements.txt and declare in install_requires

* Remove requirements.txt from tox.ini

* Update and pin all dependencies and sub-dependencies

* Update for breaking changes

* Reformat

* Update docs/requirements.txt and tox.ini requirements

* Add 3.7 to identifiers and travis/tox builds

* Attempt at fixing the travis build matrix

* Attempt #2

* Attempt 3

* aiohttp.ClientSession.close() -> detach() in sync code

* Add raven-aiohttp to requirements

* Fix stuff in setup.py

 - Added discord.py back into requirements list
 - Fix typo in alabaster extra requirement

Also in the Pipfile:
 - Removed allow_prereleases and explicitly pinned black, since this is the only dep we want a prerelease for.

* Update to Rapptz/discord.py@8ccb98d395

* Add proper 3.7 build in Travis

See travis-ci/travis-ci#9815

* Which version of 3.6 does Xenial install then?

* Maybe we should stop pipenv installing useless stuff

* Nevermind, back to specific minor version

* Remove lots of WET dependency stuff

* Fix egg fragment for dependency link

.travis.yml

@@ -1,33 +1,37 @@
-dist: trusty
+dist: xenial
 language: python
 cache: pip
 notifications:
   email: false
+sudo: true
 
 python:
-- 3.6.5
+- 3.6.6
+- 3.7
 env:
   global:
     PIPENV_IGNORE_VIRTUALENVS=1
   matrix:
-    - TOXENV=py
-    - TOXENV=docs
-    - TOXENV=style
+    TOXENV=py
 
 install:
-- pip install --upgrade pip pipenv
-- pipenv install --dev
+- pip install --upgrade pip tox
 
 script:
-- pipenv run tox
+- tox
 
 jobs:
   include:
 
+    - python: 3.6.6
+      env: TOXENV=docs
+    - python: 3.6.6
+      env: TOXENV=style
+
     # These jobs only occur on tag creation for V3/develop if the prior ones succeed
     - stage: PyPi Deployment
       if: tag IS present
-      python: 3.6.5
+      python: 3.6.6
       env:
         - DEPLOYING=true
       deploy:
@@ -39,11 +43,11 @@ jobs:
           on:
             repo: Cog-Creators/Red-DiscordBot
             branch: V3/develop
-            python: 3.6.5
+            python: 3.6.6
             tags: true
     - stage: Crowdin Deployment
       if: tag IS present
-      python: 3.6.5
+      python: 3.6.6
       env:
         - DEPLOYING=true
       before_deploy:
@@ -58,5 +62,5 @@ jobs:
         on:
           repo: Cog-Creators/Red-DiscordBot
           branch: V3/develop
-          python: 3.6.5
+          python: 3.6.6
           tags: true