[GRIN-Wallet] test estimate-selection flag #45

Grin-Wallet Version:

```~/grin-wallet/target/release$ ./grin-wallet -V
grin-wallet 5.0.0-beta.4
```

Grin-Wallet Account Environment

```~/grin-wallet/target/release$ ./grin-wallet account
Password: 

____ Wallet Accounts ____

 Name    | Parent BIP-32 Derivation Path 
---------+-------------------------------
 default | m/0/0 

Command 'account' completed successfully
```

Actual Test and Results:

~/grin-wallet/target/release$ ./grin-wallet send -m -e -d grin1lavjlz3nc7aj9mjk4zuukm48q44d35wrwhfl0lejs42evppc9f5srfw5vj 2
Password: 

Estimation for sending 2.000000000:

+--------------------+-------------+----------------+
| Selection strategy | Fee         | Will be locked |
+====================+=============+================+
| smallest           | 0.023000000 | 4.000000000    |
+--------------------+-------------+----------------+
| all                | 0.023500000 | 8.016000000    |
+--------------------+-------------+----------------+

Command 'send' completed successfully



##Failed commands that I tried along the way
###(hint: the first one failed cause I forgot to have the `send` command and the rest were unwise attempts prior to realizing I need `send`)
~/grin-wallet/target/release$ ./grin-wallet -m -e -d grin1lavjlz3nc7aj9mjk4zuukm48q44d35wrwhfl0lejs42evppc9f5srfw5vj 2
error: Found argument '-m' which wasn't expected, or isn't valid in this context

USAGE:
    grin-wallet [FLAGS] [OPTIONS] [SUBCOMMAND]

For more information try --help



~/grin-wallet/target/release$ ./grin-wallet -e -d grin1lavjlz3nc7aj9mjk4zuukm48q44d35wrwhfl0lejs42evppc9f5srfw5vj 2
error: Found argument '-e' which wasn't expected, or isn't valid in this context

USAGE:
    grin-wallet [FLAGS] [OPTIONS] [SUBCOMMAND]

For more information try --help



~/grin-wallet/target/release$ ./grin-wallet -e grin1lavjlz3nc7aj9mjk4zuukm48q44d35wrwhfl0lejs42evppc9f5srfw5vj 2
error: Found argument '-e' which wasn't expected, or isn't valid in this context

USAGE:
    grin-wallet [FLAGS] [OPTIONS] [SUBCOMMAND]

For more information try --help