Loosen constraint

Actions use semver, there is no reason to pin so hard to a specific
version.

Author: greg0ire

.github/workflows/continuous-integration.yml

@@ -23,7 +23,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v2.0.0"
+        uses: "actions/checkout@v2"
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@v2"
@@ -56,7 +56,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v2.0.0"
+        uses: "actions/checkout@v2"
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@v2"
@@ -96,7 +96,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v2.0.0"
+        uses: "actions/checkout@v2"
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@v2"
@@ -130,7 +130,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v2.0.0"
+        uses: "actions/checkout@v2"
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@v2"