Bump pygments from 2.3.1 to 2.7.4

Bumps [pygments](https://github.com/pygments/pygments) from 2.3.1 to 2.7.4.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.3.1...2.7.4)

Signed-off-by: dependabot[bot] <support@github.com>

requirements-dev.txt

@@ -4,26 +4,62 @@
 #
 #    pip-compile --output-file requirements-dev.txt requirements-dev.in
 #
-astroid==2.1.0            # via pylint
-certifi==2018.11.29       # via requests
-chardet==3.0.4            # via requests
+astroid==2.1.0
+    # via pylint
+certifi==2018.11.29
+    # via requests
+chardet==3.0.4
+    # via requests
 coverage==4.0.3
+    # via
+    #   -r requirements-dev.in
+    #   python-coveralls
 detect-secrets==0.11.4
+    # via -r requirements-dev.in
 flake8==3.6.0
-idna==2.8                 # via requests
+    # via -r requirements-dev.in
+idna==2.8
+    # via requests
 isort==4.3.4
-lazy-object-proxy==1.3.1  # via astroid
-mccabe==0.6.1             # via flake8, pylint
+    # via
+    #   -r requirements-dev.in
+    #   pylint
+lazy-object-proxy==1.3.1
+    # via astroid
+mccabe==0.6.1
+    # via
+    #   flake8
+    #   pylint
 pudb==2018.1
+    # via -r requirements-dev.in
 pycodestyle==2.4.0
-pyflakes==2.0.0           # via flake8
-pygments==2.3.1           # via pudb
+    # via
+    #   -r requirements-dev.in
+    #   flake8
+pyflakes==2.0.0
+    # via flake8
+pygments==2.7.4
+    # via pudb
 pylint==2.2.2
+    # via -r requirements-dev.in
 python-coveralls==2.9.1
+    # via -r requirements-dev.in
 pyyaml==4.2b4
-requests==2.21.0          # via python-coveralls
-six==1.12.0               # via astroid, python-coveralls
-urllib3==1.24.2           # via requests
-urwid==2.0.1              # via pudb
+    # via
+    #   -r requirements-dev.in
+    #   detect-secrets
+    #   python-coveralls
+requests==2.21.0
+    # via python-coveralls
+six==1.12.0
+    # via
+    #   astroid
+    #   python-coveralls
+urllib3==1.24.2
+    # via requests
+urwid==2.0.1
+    # via pudb
 wheel==0.32.3
-wrapt==1.11.0             # via astroid
+    # via -r requirements-dev.in
+wrapt==1.11.0
+    # via astroid