Add bumpver configuration

[agjohnson]

This is directly called from ops/deploy, so usage of this tool is
abstracted and not super important.

It's easy to use however, and has a string input method, instead of
incrementing each part individually, a la bump2version.

% bumpver update --dry --set-version "8.0.0"
INFO    - fetching tags from remote (to turn off use: -n / --no-fetch)
INFO    - Old Version: 7.4.2
INFO    - New Version: 8.0.0
--- docs/conf.py
+++ docs/conf.py
@@ -67,7 +67,7 @@
 copyright = '2010-{}, Read the Docs, Inc & contributors'.format(
     timezone.now().year
 )
-version = "7.4.2"
+version = "8.0.0"
 release = version
 exclude_patterns = ['_build']
 default_role = 'obj'
--- package.json
+++ package.json
@@ -1,6 +1,6 @@
 {
   "name": "readthedocs",
-  "version": "7.4.2",
+  "version": "8.0.0",
   "description": "Read the Docs build dependencies",
   "author": "Read the Docs, Inc <[email protected]>",
   "scripts": {
--- readthedocs/__init__.py
+++ readthedocs/__init__.py
@@ -2,5 +2,5 @@

 import os.path

-__version__ = "7.4.2"
+__version__ = "8.0.0"

--- setup.cfg
+++ setup.cfg
@@ -29,7 +29,7 @@
 github_repo = readthedocs.org

 [bumpver]
-current_version = "7.4.2"
+current_version = "8.0.0"
 version_pattern = "MAJOR.MINOR.PATCH[TAGNUM]"
 commit_message = "Bump version {old_version} -> {new_version}"
 commit = False

[ericholscher]

This seems like a cleaner approach. I'm 👍 assuming we integrate it in our deploy scripts.