Remove quotes from dependency versions

Single-quoted version numbers in requirements files causes the following
error in recent packaging versions:

    pkg_resources.extern.packaging.requirements.InvalidRequirement: Expected end or semicolon (after name and no valid version specifier)
        pytest-cov>='2.12.0'

Remove the quotes to avoid the error (and better comply with PEP 508?).

Signed-off-by: Kevin Locke <kevin@kevinlocke.name>

requirements/dev.in

@@ -1,7 +1,7 @@
 # Abstract top-level development dependencies (e.g. linters and other tools)
 # Support for pyproject.toml added in 1.7.1
 # https://github.com/PyCQA/bandit/pull/401
-bandit[toml] >= '1.7.1'
+bandit[toml] >= 1.7.1
 black
 blacken-docs
 flake8
@@ -11,12 +11,12 @@ flake8-docstrings
 # Disabled pending
 # https://github.com/globality-corp/flake8-logging-format/pull/33
 #flake8-logging-format
-flake8-rst-docstrings >= '0.0.11'
+flake8-rst-docstrings >= 0.0.11
 isort
 mypy
 # Support for pyproject.toml added in 6.1.0
 # https://github.com/PyCQA/pydocstyle/pull/534
-pydocstyle >= '6.1.0'
+pydocstyle >= 6.1.0
 # Required for `setup.py check --restructuredtext --strict`.  Otherwise:
 # warning: check: Cannot analyze code. Pygments package not found.
 pygments

requirements/test.in

@@ -3,4 +3,4 @@ coverage[toml]
 pytest
 # Support for pyproject.toml added in 2.12.0
 # https://github.com/pytest-dev/pytest-cov/pull/410
-pytest-cov >= '2.12.0'
+pytest-cov >= 2.12.0