Fix accidental printing of files named 'cache'

This also adds two regression tests, so this will hopefully not pop up
again.

closes #557

Cargo.lock

@@ -1,3 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "adler32"
 version = "1.0.3"

src/clap_app.rs

@@ -18,7 +18,6 @@ pub fn build_app(interactive_output: bool) -> ClapApp<'static, 'static> {
         .global_setting(AppSettings::DeriveDisplayOrder)
         .global_setting(AppSettings::UnifiedHelpMessage)
         .global_setting(AppSettings::HidePossibleValuesInHelp)
-        .setting(AppSettings::InferSubcommands)
         .setting(AppSettings::ArgsNegateSubcommands)
         .setting(AppSettings::DisableHelpSubcommand)
         .setting(AppSettings::VersionlessSubcommands)

tests/examples/cache

@@ -0,0 +1 @@
+test

tests/integration_tests.rs

@@ -448,3 +448,18 @@ fn utf16() {
         .success()
         .stdout(std::str::from_utf8(b"\xEF\xBB\xBFhello world\n").unwrap());
 }
+
+#[test]
+fn can_print_file_named_cache() {
+    bat()
+        .arg("cache")
+        .assert()
+        .success()
+        .stdout("test\n")
+        .stderr("");
+}
+
+#[test]
+fn does_not_print_unwanted_file_named_cache() {
+    bat_with_config().arg("cach").assert().failure();
+}