rename disks to filesystems

src/test/df-test.js

@@ -16,11 +16,11 @@ describe('System', function () {
     before(setup);
     after(cleanup);
 
-    it('can get disks', async function () {
+    it('can get filesystems', async function () {
         // does not work on archlinux 8!
         if (require('child_process').execSync('uname -a').toString().indexOf('-arch') !== -1) return;
 
-        const disks = await df.disks();
+        const disks = await df.filesystems();
         expect(disks).to.be.ok();
         expect(disks.some(d => d.mountpoint === '/')).to.be.ok();
     });