tweaks for changelog, call next version 2.8.0

HISTORY.rst

@@ -2,22 +2,26 @@
 History
 =======
 
-2.7.3 (2020-10-05)
+2.8.0 (2020-10-05)
 ------------------
 
+* Dropped support for Python 3.5.
 * Add ``delta_degC`` and ``delta_degF`` units to support temperature difference
-  arithmetic. See `PR #152 <https://github.com/yt-project/unyt/pull/152>`_. Thank you
-  to Lee Johnston (@l-johnston on GitHub) for the contribution.
+  arithmetic. See `PR #152
+  <https://github.com/yt-project/unyt/pull/152>`_. Thank you to Lee Johnston
+  (@l-johnston on GitHub) for the contribution.
 * Fix an issue where a subsequent load of the unit registry with units that are
   equal but not identical leads to a crash. See `PR #158
   <https://github.com/yt-project/unyt/pull/158>`_. Thank you to Matthew Turk
   (@matthewturk on GitHub) for the initial bug report and fix.
 * Add force unit ``kip`` and pressure unit ``psi``. Thank you to P. Talley
-  (@otaithleigh on GitHub) for the contribution.
-* Fix an issue where arithmetic operations on units defined in different registries
-  and having the conversion defined in one direction would lead to a crash.
-  See `PR #164 <https://github.com/yt-project/unyt/pull/164>`_. Thank you to
-  Clément Robert (@neutrinoceros on GitHub) for the initial bug report and fix.
+  (@otaithleigh on GitHub) for the contribution. See `PR #162
+  <https://github.com/yt-project/unyt/pull/162>`_.
+* Fix an issue where arithmetic operations on units defined in different
+  registries and having the conversion defined in one direction would lead to a
+  crash.  See `PR #164 <https://github.com/yt-project/unyt/pull/164>`_. Thank
+  you to Clément Robert (@neutrinoceros on GitHub) for the initial bug report
+  and fix.
 
 
 2.7.2 (2020-06-29)