chore: add github workflow (#6)

.github/workflows/check.yml

@@ -0,0 +1,27 @@
+name: CI
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: install prerequisites
+      run: sudo apt-get install -y perl libperl-critic-perl perltidy
+    - name: perl check
+      run: perl -c btrfs-list
+    - name: perlcritic
+      run: perlcritic btrfs-list
+    - name: perltidy
+      run: |
+        perltidy --paren-tightness=2 --square-bracket-tightness=2 --brace-tightness=2 --maximum-line-length=180 btrfs-list
+        if cmp btrfs-list btrfs-list.tdy; then
+          echo "OK: perltidy didn't find any change to make"
+        else
+          echo "KO: perltidy found changes to make:"
+          diff -u btrfs-list btrfs-list.tdy
+          exit 1
+        fi

btrfs-list

@@ -215,7 +215,7 @@ if (defined $opt_snap_max_used) {
     $opt_snap_max_used = human2raw($opt_snap_max_used);
 }
 
-if ($opt_color eq 'never' || ($opt_color eq 'auto' && !-t 1)) {
+if ($opt_color eq 'never' || ($opt_color eq 'auto' && !-t 1)) {    ## no critic
     $ENV{'ANSI_COLORS_DISABLED'} = 1;
 }