Update version

ChangeLog.rst

-7.0.0 - TBD
------------
+7.0.0 - 2020-07-05
+------------------
 
 * Reduced the library size. For example, on macOS a stripped test binary
   statically linked with {fmt} `shrank from ~368k to less than 100k

doc/build.py

@@ -6,7 +6,7 @@ import errno, os, shutil, sys, tempfile
 from subprocess import check_call, check_output, CalledProcessError, Popen, PIPE
 from distutils.version import LooseVersion
 
-versions = ['1.0.0', '1.1.0', '2.0.0', '3.0.2', '4.0.0', '4.1.0', '5.0.0', '5.1.0', '5.2.0', '5.2.1', '5.3.0', '6.0.0', '6.1.0', '6.1.1', '6.1.2', '6.2.0', '6.2.1']
+versions = ['1.0.0', '1.1.0', '2.0.0', '3.0.2', '4.0.0', '4.1.0', '5.0.0', '5.1.0', '5.2.0', '5.2.1', '5.3.0', '6.0.0', '6.1.0', '6.1.1', '6.1.2', '6.2.0', '6.2.1', '7.0.0']
 
 def pip_install(package, commit=None, **kwargs):
   "Install package using pip."