Move option parsing logic from src/delete/main.rs to newly introduced delete::cli module.

Changes:
- Introduce "delete::cli" module in "hagrid" crate.
- Move option parsing logic there from src/delete/main.rs (former src/delete.rs).

src/delete/cli.rs

@@ -0,0 +1,25 @@
+use structopt::StructOpt;
+use std::path::PathBuf;
+
+#[derive(Debug, StructOpt)]
+#[structopt(
+    name = "hagrid-delete",
+    about = "Deletes (address, key)-binding(s), and/or a key(s)."
+)]
+pub(crate)  struct Opt {
+    /// Base directory.
+    #[structopt(parse(from_os_str))]
+    pub(crate) base: PathBuf,
+
+    /// E-Mail address, Fingerprint, or KeyID of the TPK to delete.
+    /// If a Fingerprint or KeyID is given, --all is implied.
+    pub(crate) query: String,
+
+    /// Also delete all bindings.
+    #[structopt(long = "all-bindings")]
+    pub(crate) all_bindings: bool,
+
+    /// Also delete all bindings and the key.
+    #[structopt(long = "all")]
+    pub(crate) all: bool,
+}

src/delete/main.rs

@@ -1,34 +1,10 @@
 //! Deletes (address, key)-binding(s), and/or a key(s).
 
+mod cli;
+
 use std::convert::TryInto;
-use std::path::PathBuf;
-
 use structopt::StructOpt;
-
-use hagrid_database::{Database, KeyDatabase, Query, types::Fingerprint};
-
-#[derive(Debug, StructOpt)]
-#[structopt(
-    name = "hagrid-delete",
-    about = "Deletes (address, key)-binding(s), and/or a key(s)."
-)]
-pub struct Opt {
-    /// Base directory.
-    #[structopt(parse(from_os_str))]
-    base: PathBuf,
-
-    /// E-Mail address, Fingerprint, or KeyID of the TPK to delete.
-    /// If a Fingerprint or KeyID is given, --all is implied.
-    query: String,
-
-    /// Also delete all bindings.
-    #[structopt(long = "all-bindings")]
-    all_bindings: bool,
-
-    /// Also delete all bindings and the key.
-    #[structopt(long = "all")]
-    all: bool,
-}
+use hagrid_database::{types::Fingerprint, Database, KeyDatabase, Query};
 
 fn main() {
     if let Err(e) = real_main() {
@@ -44,7 +20,7 @@ fn main() {
 }
 
 fn real_main() -> anyhow::Result<()> {
-    let opt = Opt::from_args();
+    let opt = cli::Opt::from_args();
     let db = KeyDatabase::new_file(opt.base.canonicalize()?)?;
     delete(&db, &opt.query.parse()?, opt.all_bindings, opt.all)
 }