Add linting to YAML files

Author: QuLogic

.appveyor.yml

@@ -2,6 +2,7 @@
 # http://tjelvarolsson.com/blog/how-to-continuously-test-your-python-code-on-windows-using-appveyor/
 # https://packaging.python.org/en/latest/appveyor/
 # https://github.com/rmcgibbo/python-appveyor-conda-example
+---
 
 # Backslashes in quotes need to be escaped: \ -> "\\"
 branches:
@@ -38,7 +39,7 @@ environment:
 # We always use a 64-bit machine, but can build x86 distributions
 # with the PYTHON_ARCH variable
 platform:
-    - x64
+  - x64
 
 # all our python builds have to happen in tests_script...
 build: false
@@ -79,10 +80,13 @@ test_script:
   - if x%TEST_ALL% == xyes conda install -q ffmpeg inkscape miktex
   # missing packages on conda-forge for imagemagick
   # This install sometimes failed randomly :-(
-  #- choco install imagemagick
+  # - choco install imagemagick
 
   # Test import of tkagg backend
-  - python -c "import matplotlib as m; m.use('tkagg'); import matplotlib.pyplot as plt; print(plt.get_backend())"
+  - python -c
+    "import matplotlib as m; m.use('tkagg');
+    import matplotlib.pyplot as plt;
+    print(plt.get_backend())"
   # tests
   - echo The following args are passed to pytest %PYTEST_ARGS%
   - pytest %PYTEST_ARGS%

.circleci/config.yml

@@ -17,7 +17,8 @@ commands:
             export git_log=$(git log --max-count=1 --pretty=format:"%B" | tr "\n" " ")
             echo "Got commit message:"
             echo "${git_log}"
-            if [[ -v CIRCLE_PULL_REQUEST ]] && [[ $git_log =~ (\[skip circle\]|\[circle skip\]|\[skip doc\]|\[doc skip\]) ]]; then
+            if [[ -v CIRCLE_PULL_REQUEST ]] &&
+               [[ $git_log =~ (\[skip circle\]|\[circle skip\]|\[skip doc\]|\[doc skip\]) ]]; then
               echo "Skip detected, exiting job ${CIRCLE_JOB} for PR ${CIRCLE_PULL_REQUEST}."
               circleci-agent step halt;
             fi
@@ -71,8 +72,12 @@ commands:
           name: Install custom fonts
           command: |
             mkdir -p ~/.local/share/fonts
-            wget -nc https://github.com/google/fonts/blob/master/ofl/felipa/Felipa-Regular.ttf?raw=true -O ~/.local/share/fonts/Felipa-Regular.ttf || true
-            wget -nc https://github.com/ipython/xkcd-font/blob/master/xkcd-script/font/xkcd-script.ttf?raw=true -O ~/.local/share/fonts/xkcd-Script.ttf || true
+            wget -nc \
+              https://github.com/google/fonts/blob/master/ofl/felipa/Felipa-Regular.ttf?raw=true \
+              -O ~/.local/share/fonts/Felipa-Regular.ttf || true
+            wget -nc \
+              https://github.com/ipython/xkcd-font/blob/master/xkcd-script/font/xkcd-script.ttf?raw=true \
+              -O ~/.local/share/fonts/xkcd-Script.ttf || true
             fc-cache -f -v
       - save_cache:
           key: fonts-4

.github/FUNDING.yml

@@ -1,3 +1,4 @@
+---
 # These are supported funding model platforms
 github: [matplotlib, numfocus]
 custom: https://numfocus.org/donate-to-matplotlib

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,3 +1,4 @@
+---
 name: Bug Report
 description: Report a bug or issue with Matplotlib.
 title: "[Bug]: "
@@ -6,7 +7,7 @@ body:
     id: summary
     attributes:
       label: Bug summary
-      description:  Describe the bug in 1-2 short sentences
+      description: Describe the bug in 1-2 short sentences
       placeholder:
       value:
     validations:

.github/ISSUE_TEMPLATE/config.yml

@@ -1,5 +1,7 @@
-# Ref: https://help.github.com/en/github/building-a-strong-community/configuring-issue-templates-for-your-repository#configuring-the-template-chooser
-blank_issues_enabled: true # default
+# Reference:
+# https://help.github.com/en/github/building-a-strong-community/configuring-issue-templates-for-your-repository#configuring-the-template-chooser
+---
+blank_issues_enabled: true  # default
 contact_links:
   - name: Question/Support/Other
     url: https://discourse.matplotlib.org

.github/ISSUE_TEMPLATE/documentation.yml

@@ -1,3 +1,4 @@
+---
 name: Documentation
 description: Create a report to help us improve the documentation
 title: "[Doc]: "
@@ -9,7 +10,8 @@ body:
       label: Documentation Link
       description: |
         Link to any documentation or examples that you are referencing.
-        Suggested improvements should be based on the development version of the docs: https://matplotlib.org/devdocs/
+        Suggested improvements should be based on the development version of the docs:
+        https://matplotlib.org/devdocs/
       placeholder: https://matplotlib.org/devdocs/...
   - type: textarea
     id: problem

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -1,12 +1,14 @@
+---
 name: Feature Request
 description: Suggest something to add to Matplotlib!
 title: "[ENH]: "
 labels: [New feature]
 body:
   - type: markdown
     attributes:
-      value: |
-         Please search the [issues](https://github.com/matplotlib/matplotlib/issues) for relevant feature requests before creating a new feature request.
+      value: >-
+        Please search the [issues](https://github.com/matplotlib/matplotlib/issues) for relevant feature
+        requests before creating a new feature request.
   - type: textarea
     id: problem
     attributes:

.github/ISSUE_TEMPLATE/maintenance.yml

@@ -1,3 +1,4 @@
+---
 name: Maintenance
 description: Help improve performance, usability and/or consistency.
 title: "[MNT]: "
@@ -7,7 +8,7 @@ body:
     id: summary
     attributes:
       label: Summary
-      description:  Please provide 1-2 short sentences that succinctly describes what could be improved.
+      description: Please provide 1-2 short sentences that succinctly describes what could be improved.
     validations:
       required: true
   - type: textarea

.github/ISSUE_TEMPLATE/tag_proposal.yml

@@ -1,3 +1,4 @@
+---
 name: Tag Proposal
 description: Suggest a new tag or subcategory for the gallery of examples
 title: "[Tag]: "

.github/codecov.yml

@@ -1,10 +1,11 @@
 # codecov used to be able to find this anywhere, now we have to manually
 # tell it where to look
+---
 comment: false
 
 codecov:
   notify:
-    require_ci_to_pass: no
+    require_ci_to_pass: false
 
 coverage:
   status: