ishell 0.1.2

Pseudo-interactive shell interface for Rust
Documentation
### IShell - (pseudo)interactive shell

The main goal was to make a shell interface that remembers `cd` commands.

You can create a new shell by simply doing:
```rust
// Parameter here is an Option<String> corresponding to
// the initial directory, from where the command will be ran.
let shell = IShell::new(None);
```

You can also specify where to open the shell initially:
```rust
// No matter from where you run the program,
// the shell will always be created at ~/Desktop
let desktop_shell = IShell::new("~/Desktop");
```

To run a command through your shell, you can do the following:
```rust
shell.run_command("echo 'Hello, World!'");
```

The `run_command` method also returns `std::process::Output` type.

You can also call
```rust
shell.forget_current_directory();
```
To make the shell set current directory to the initial directory specified.
If initial directory wasn't specified, then this sets the current shell directory to
the `$PWD` of the terminal running the program.