Bump pyyaml from 3.13 to 5.1

[dependabot[bot]]

Bumps pyyaml from 3.13 to 5.1.

Changelog

Sourced from pyyaml's changelog.

5.1 (2019-03-13)

• yaml/pyyaml#35 -- Some modernization of the test running
• yaml/pyyaml#42 -- Install tox in a virtualenv
• yaml/pyyaml#45 -- Allow colon in a plain scalar in a flow context
• yaml/pyyaml#48 -- Fix typos
• yaml/pyyaml#55 -- Improve RepresenterError creation
• yaml/pyyaml#59 -- Resolves #57, update readme issues link
• yaml/pyyaml#60 -- Document and test Python 3.6 support
• yaml/pyyaml#61 -- Use Travis CI built in pip cache support
• yaml/pyyaml#62 -- Remove tox workaround for Travis CI
• yaml/pyyaml#63 -- Adding support to Unicode characters over codepoint 0xffff
• yaml/pyyaml#75 -- add 3.12 changelog
• yaml/pyyaml#76 -- Fallback to Pure Python if Compilation fails
• yaml/pyyaml#84 -- Drop unsupported Python 3.3
• yaml/pyyaml#102 -- Include license file in the generated wheel package
• yaml/pyyaml#105 -- Removed Python 2.6 & 3.3 support
• yaml/pyyaml#111 -- Remove commented out Psyco code
• yaml/pyyaml#129 -- Remove call to ord in lib3 emitter code
• yaml/pyyaml#149 -- Test on Python 3.7-dev
• yaml/pyyaml#158 -- Support escaped slash in double quotes "/"
• yaml/pyyaml#175 -- Updated link to pypi in release announcement
• yaml/pyyaml#181 -- Import Hashable from collections.abc
• yaml/pyyaml#194 -- Reverting yaml/pyyaml#74
• yaml/pyyaml#195 -- Build libyaml on travis
• yaml/pyyaml#196 -- Force cython when building sdist
• yaml/pyyaml#254 -- Allow to turn off sorting keys in Dumper (2)
• yaml/pyyaml#256 -- Make default_flow_style=False
• yaml/pyyaml#257 -- Deprecate yaml.load and add FullLoader and UnsafeLoader classes
• yaml/pyyaml#261 -- Skip certain unicode tests when maxunicode not > 0xffff
• yaml/pyyaml#263 -- Windows Appveyor build

Commits

• e471e86 Updates for 5.1 release
• 9141e90 Windows Appveyor build
• d6cbff6 Skip certain unicode tests when maxunicode not > 0xffff
• 69103ba Update .travis.yml to use libyaml 0.2.2
• 91c9435 Squash/merge pull request #105 from nnadeau/patch-1
• 507a464 Make default_flow_style=False
• 07c88c6 Allow to turn off sorting keys in Dumper
• 611ba39 Include license file in the generated wheel package
• 857dff1 Apply FullLoader/UnsafeLoader changes to lib3
• 0cedb2a Deprecate/warn usage of yaml.load(input)
• Additional commits viewable in compare view

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