Use npm@7 in GH CI

Author: pluma

.github/workflows/docs.yml

@@ -25,6 +25,7 @@ jobs:
           ref: gh-pages
           path: gh-pages
 
+      - run: npm install -g npm@7
       - run: npm install
 
       - name: Set TAG env to devel

.github/workflows/tests.yml

@@ -22,6 +22,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
+      - run: npm install -g npm@7
       - run: npm install
       - run: npm test
         env:

.github/workflows/web.yml

@@ -21,5 +21,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
+      - run: npm install -g npm@7
       - run: npm install
       - run: node smoke-test.js