Bump version to 1.0.0 and update CHANGELOG (arrow-py#924)

* Start drafting changelog for 1.0.0 release

* Increment version and continue drafting changelog

* Changes based on comments

CHANGELOG.rst

@@ -1,6 +1,35 @@
 Changelog
 =========
 
+1.0.0 (2021-02-24)
+------------------
+
+After 8 years we're pleased to announce Arrow v1.0. Thanks to the entire Python community for helping make Arrow the amazing package it is today!
+
+- [CHANGE] Arrow has **dropped support** for Python 2.7 and 3.5.
+- [CHANGE] There are multiple **breaking changes** with this release, please see the `migration guide <https://github.com/arrow-py/arrow/issues/832>`_ for a complete overview.
+- [CHANGE] Arrow is now following `semantic versioning <https://semver.org/>`_.
+- [CHANGE] Made ``humanize`` granularity="auto" limits more accurate to reduce strange results.
+- [NEW] Added support for Python 3.9.
+- [NEW] Added a new keyword argument "exact" to ``span``, ``span_range`` and ``interval`` methods. This makes timespans begin at the start time given and not extend beyond the end time given, for example:
+
+..code-block:: python
+    >>> start = Arrow(2021, 2, 5, 12, 30)
+    >>> end = Arrow(2021, 2, 5, 17, 15)
+    >>> for r in arrow.Arrow.span_range('hour', start, end, exact=True):
+    ...     print(r)
+    ...
+    (<Arrow [2021-02-05T12:30:00+00:00]>, <Arrow [2021-02-05T13:29:59.999999+00:00]>)
+    (<Arrow [2021-02-05T13:30:00+00:00]>, <Arrow [2021-02-05T14:29:59.999999+00:00]>)
+    (<Arrow [2021-02-05T14:30:00+00:00]>, <Arrow [2021-02-05T15:29:59.999999+00:00]>)
+    (<Arrow [2021-02-05T15:30:00+00:00]>, <Arrow [2021-02-05T16:29:59.999999+00:00]>)
+    (<Arrow [2021-02-05T16:30:00+00:00]>, <Arrow [2021-02-05T17:14:59.999999+00:00]>)
+
+- [NEW] Arrow now natively supports PEP 484-style type annotations.
+- [FIX] Fixed handling of maximum permitted timestamp on Windows systems.
+- [FIX] Corrections to French, German, Japanese and Norwegian locales.
+- [INTERNAL] Raise more appropriate errors when string parsing fails to match.
+
 0.17.0 (2020-10-2)
 -------------------
 

arrow/_version.py

@@ -1 +1 @@
-__version__ = "0.17.0"
+__version__ = "1.0.0"