Use "context" to contain run details (#14)

* Create "context" to contain run details

* Use context in tests and benchmarks

src/context.rs

@@ -0,0 +1,30 @@
+use clap::ArgMatches;
+use std::env;
+use std::path::PathBuf;
+
+pub struct Context<'a> {
+    pub current_dir: PathBuf,
+    pub arguments: ArgMatches<'a>,
+}
+
+impl<'a> Context<'a> {
+    pub fn new(arguments: ArgMatches) -> Context {
+        // TODO: Currently gets the physical directory. Get the logical directory.
+        let current_dir = env::current_dir().expect("Unable to identify current directory.");
+
+        Context {
+            current_dir,
+            arguments,
+        }
+    }
+
+    pub fn new_with_dir<T>(arguments: ArgMatches, dir: T) -> Context
+    where
+        T: Into<PathBuf>,
+    {
+        Context {
+            current_dir: dir.into(),
+            arguments,
+        }
+    }
+}