internal: change datetime implementation

Rework our implementation of tarantool.Datetime class. Previously it had
relied on pandas.Timestamp and pandas.Timedelta. There were user
complaints about pandas as a requirement since it's rather heavy. Now
our implementation of datetime uses built-in datetime.datetime,
datetime.timedelta and other built-in tools.

It is expected that the implementation change wouldn't affect users, but
some minor behavior traits were broken in this patch:
- Now we rely on datetime argument validation which if differs from
  pandas one. For example, it doesn't allow overflows for fields.
  Exceptions that user may receive from internal datetime are, of
  course, had changed as well.
- We drop the support of `__eq__` for pandas.Timestamp. We simply
  compared underlying pandas.Timestamp with argument one, and now it's
  impossible. If the feature would be required later, we may implement
  its comparison in some compatible way.
- __repr__ has been changed since internal representation has been
  changed as well.

Closes #290

Author: DifferentialOrange

Diff for: CHANGELOG.md

@@ -11,6 +11,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Migrate to built-in `Warning` instead of a custom one.
 - Migrate to built-in `RecursionError` instead of a custom one.
 - Collect full exception traceback.
+- Rework `tarantool.Datetime` implementation to use built-in
+  `datetime.datetime`. External changes are as follows. Some of them
+  are **breaking**.
+  - Package no longer depends on `pandas` (#290).
+  - `__repr__` has been changed.
+  - Input arguments are validated with `datetime.datetime` rules.
+  - Class is no longer expected to throw `pandas.Timestamp`
+    exceptions. `datetime.datetime` exceptions will
+    be thrown instead of them.
+  - Drop the support of `__eq__` operator for `pandas.Timestamp`.
 
 ## 0.12.1 - 2023-02-28
 

Diff for: docs/source/conf.py

@@ -344,7 +344,6 @@
 intersphinx_mapping = {
     'python': ('http://docs.python.org/', None),
     'msgpack': ('https://msgpack-python.readthedocs.io/en/latest/', None),
-    'pandas': ('https://pandas.pydata.org/docs/', None),
     'pytz': ('https://pytz.sourceforge.net/', None),
 }
 

Diff for: requirements.txt

@@ -1,4 +1,3 @@
 msgpack
-pandas
 pytz
 dataclasses; python_version <= '3.6'

Diff for: rpm/SPECS/python-tarantool.spec

@@ -29,7 +29,6 @@ Python client library for Tarantool.}
 %package -n python3-%{srcname}
 
 Requires:       python3-msgpack
-Requires:       python3-pandas
 Requires:       python3-pytz
 
 Summary:        %{summary}