Add 'exact' keyword in span_range, span and interval methods

[svanita00]

Pull Request Checklist

Thank you for taking the time to improve Arrow! Before submitting your pull request, please check all appropriate boxes:

• [x] 🧪 Added tests for changed code.
• [x] 🛠️ All tests pass when run locally (run tox or make test to find out!).
• [x] 🧹 All linting checks pass when run locally (run tox -e lint or make lint to find out!).
• [ ] 📚 Updated documentation for changed code.
• [x] ⏩ Code is up-to-date with the master branch.

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Description of Changes

Merged PR #817 with updated master. Added edge cases in span_range function when exact keyword is True. Added correlated tests for span_range.

Closes: #498

[codecov[bot]]

Codecov Report

Merging #888 (57a5184) into master (0aebf57) will not change coverage. The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #888   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            9         9           
  Lines         1798      1817   +19     
  Branches       313       320    +7     
=========================================
+ Hits          1798      1817   +19     

Impacted Files	Coverage Δ
arrow/arrow.py	100.00% <100.00%> (ø)

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[svanita00]

I'm not sure why the lint is failing here, I ran it locally and it passed there..

[systemcatch]

Seems like the bug found in the old PR is now fixed. :+1:

from datetime import datetime
import arrow

start = datetime(2013, 5, 5, 12, 30)
end = datetime(2013, 5, 5, 12, 40)

for r in arrow.Arrow.span_range('minute', start, end, exact=True):
    print(r)

Old bug

(<Arrow [2013-05-05T12:30:00+00:00]>, <Arrow [2013-05-05T12:30:59.999999+00:00]>)
(<Arrow [2013-05-05T12:31:00+00:00]>, <Arrow [2013-05-05T12:31:59.999999+00:00]>)
(<Arrow [2013-05-05T12:32:00+00:00]>, <Arrow [2013-05-05T12:32:59.999999+00:00]>)
(<Arrow [2013-05-05T12:33:00+00:00]>, <Arrow [2013-05-05T12:33:59.999999+00:00]>)
(<Arrow [2013-05-05T12:34:00+00:00]>, <Arrow [2013-05-05T12:34:59.999999+00:00]>)
(<Arrow [2013-05-05T12:35:00+00:00]>, <Arrow [2013-05-05T12:35:59.999999+00:00]>)
(<Arrow [2013-05-05T12:36:00+00:00]>, <Arrow [2013-05-05T12:36:59.999999+00:00]>)
(<Arrow [2013-05-05T12:37:00+00:00]>, <Arrow [2013-05-05T12:37:59.999999+00:00]>)
(<Arrow [2013-05-05T12:38:00+00:00]>, <Arrow [2013-05-05T12:38:59.999999+00:00]>)
(<Arrow [2013-05-05T12:39:00+00:00]>, <Arrow [2013-05-05T12:39:59.999999+00:00]>)
(<Arrow [2013-05-05T12:40:00+00:00]>, <Arrow [2013-05-05T12:39:59.999999+00:00]>)

New correct

(<Arrow [2013-05-05T12:30:00+00:00]>, <Arrow [2013-05-05T12:30:59.999999+00:00]>)
(<Arrow [2013-05-05T12:31:00+00:00]>, <Arrow [2013-05-05T12:31:59.999999+00:00]>)
(<Arrow [2013-05-05T12:32:00+00:00]>, <Arrow [2013-05-05T12:32:59.999999+00:00]>)
(<Arrow [2013-05-05T12:33:00+00:00]>, <Arrow [2013-05-05T12:33:59.999999+00:00]>)
(<Arrow [2013-05-05T12:34:00+00:00]>, <Arrow [2013-05-05T12:34:59.999999+00:00]>)
(<Arrow [2013-05-05T12:35:00+00:00]>, <Arrow [2013-05-05T12:35:59.999999+00:00]>)
(<Arrow [2013-05-05T12:36:00+00:00]>, <Arrow [2013-05-05T12:36:59.999999+00:00]>)
(<Arrow [2013-05-05T12:37:00+00:00]>, <Arrow [2013-05-05T12:37:59.999999+00:00]>)
(<Arrow [2013-05-05T12:38:00+00:00]>, <Arrow [2013-05-05T12:38:59.999999+00:00]>)
(<Arrow [2013-05-05T12:39:00+00:00]>, <Arrow [2013-05-05T12:39:59.999999+00:00]>)