Add integration test for verbosity example

examples/verbosity/Cargo.toml

@@ -5,3 +5,6 @@ authors = ["Christopher Durham <cad97@cad97.com>"]
 
 [dependencies]
 quicli = "0.2"
+
+[dev-dependencies]
+assert_cli = "0.5.4"

examples/verbosity/tests/integration.rs

@@ -0,0 +1,54 @@
+extern crate assert_cli;
+
+#[test]
+fn no_v() {
+    assert_cli::Assert::main_binary()
+        .stderr().contains("always shown")
+        .stdout().is("0 verbose flags passed
+error logging enabled
+warn debugging disabled
+info debugging disabled
+debug debugging disabled
+trace debugging disabled")
+        .unwrap();
+}
+
+#[test]
+fn v() {
+    assert_cli::Assert::main_binary()
+        .with_args(&["-v"])
+        .stderr().contains("always shown")
+        .stderr().contains("shown at -v")
+        .stderr().doesnt_contain("shown at -vv")
+        .unwrap();
+}
+
+#[test]
+fn vv() {
+    assert_cli::Assert::main_binary()
+        .with_args(&["-vv"])
+        .stderr().contains("always shown")
+        .stderr().contains("shown at -vv")
+        .stderr().doesnt_contain("shown at -vvv")
+        .unwrap();
+}
+
+#[test]
+fn vvv() {
+    assert_cli::Assert::main_binary()
+        .with_args(&["-vvv"])
+        .stderr().contains("always shown")
+        .stderr().contains("shown at -vvv")
+        .stderr().doesnt_contain("shown at -vvvv")
+        .unwrap();
+}
+
+#[test]
+fn vvvv() {
+    assert_cli::Assert::main_binary()
+        .with_args(&["-vvvv"])
+        .stderr().contains("always shown")
+        .stderr().contains("shown at -vvvv")
+        .stdout().doesnt_contain("trace debugging disabled")
+        .unwrap();
+}