fix: use specific poetry version (#123)

**Issue #, if available:** N/A

## Description of changes:

By specifying the exact poetry version we prevent local vs remote
differences.

**Checklist**

<!--- Leave unchecked if your change doesn't seem to apply -->

* [x] Update tests
* [x] Update docs
* [x] PR title follows [conventional commit
semantics](https://www.conventionalcommits.org/en/v1.0.0-beta.2/#commit-message-for-a-fix-using-an-optional-issue-number)

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.github/workflows/ci.yml

@@ -22,8 +22,14 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}
-      - name: Run image
-        uses: abatilo/actions-poetry@v2.2.0
+      - uses: Gr1N/setup-poetry@v8
+        with:
+          poetry-version: "1.4.0"
+      - uses: actions/cache@v2
+        with:
+          path: ~/.cache/pypoetry/virtualenvs
+          key: ${{ runner.os }}-poetry-${{ hashFiles('poetry.lock') }}
+      - run: poetry --version
       - name: Install dependencies
         run: make install
       - name: Run check

.github/workflows/release.yml

@@ -19,8 +19,14 @@ jobs:
         id: vars
         run: |
           echo ::set-output name=version::$(awk '/version/{print $NF}'  pyproject.toml | sed 's/\"//g')
-      - name: Install poetry
-        uses: abatilo/actions-poetry@v2.1.3
+      - uses: Gr1N/setup-poetry@v8
+        with:
+          poetry-version: "1.4.0"
+      - uses: actions/cache@v2
+        with:
+          path: ~/.cache/pypoetry/virtualenvs
+          key: ${{ runner.os }}-poetry-${{ hashFiles('poetry.lock') }}
+      - run: poetry --version
       - name: Install dependencies
         run: make install
       - name: Run check