Command tests (#922)

* WIP command tests

* Finish marking todo tests

* update

* update

* Windows cd test ignoring

crates/nu-command/tests/commands/random/integer.rs

@@ -0,0 +1,39 @@
+use nu_test_support::{nu, pipeline};
+
+#[test]
+fn generates_an_integer() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+        random integer 42..43
+        "#
+    ));
+
+    assert!(actual.out.contains("42") || actual.out.contains("43"));
+}
+
+#[test]
+fn generates_55() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+        random integer 55..55
+        "#
+    ));
+
+    assert!(actual.out.contains("55"));
+}
+
+// FIXME: jt: needs more work
+#[ignore]
+#[test]
+fn generates_0() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+        random integer ..<1
+        "#
+    ));
+
+    assert!(actual.out.contains('0'));
+}