Fixing compile error in Anchor CPI lesson

[banescusebi]

Problem

After implementing the code in the Lab section of the Anchor CPI lesson here, I ran into the following build errors:

% anchor build
   Compiling anchor-movie-review-program v0.1.0 (/Users/s/anchor-movie-review-program/programs/anchor-movie-review-program)
    Finished release [optimized] target(s) in 1.46s
   Compiling anchor-movie-review-program v0.1.0 (/Users/s/anchor-movie-review-program/programs/anchor-movie-review-program)
error[E0599]: no function or associated item named `create_type` found for struct `anchor_spl::token::Mint` in the current scope
  --> programs/anchor-movie-review-program/src/lib.rs:89:10
   |
89 | #[derive(Accounts)]
   |          ^^^^^^^^ function or associated item not found in `Mint`
   |
   = note: this error originates in the derive macro `Accounts` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `anchor_spl::token::Mint: Discriminator` is not satisfied
  --> programs/anchor-movie-review-program/src/lib.rs:99:30
   |
99 |     pub mint: Account<'info, Mint>,
   |                              ^^^^ the trait `Discriminator` is not implemented for `anchor_spl::token::Mint`
   |
   = help: the following other types implement trait `Discriminator`:
             InitializeTokenMint
             MovieAccountState
             __idl::IdlAccount
             anchor_lang::ProgramData
             anchor_lang::idl::IdlAccount
             instruction::AddMovieReview
             instruction::DeleteMovieReview
             instruction::UpdateMovieReview

error[E0599]: no function or associated item named `insert_types` found for struct `anchor_spl::token::Mint` in the current scope
  --> programs/anchor-movie-review-program/src/lib.rs:89:10
   |
89 | #[derive(Accounts)]
   |          ^^^^^^^^ function or associated item not found in `Mint`
   |
   = note: this error originates in the derive macro `Accounts` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0599]: no function or associated item named `create_type` found for struct `anchor_spl::token::Mint` in the current scope
   --> programs/anchor-movie-review-program/src/lib.rs:107:10
    |
107 | #[derive(Accounts)]
    |          ^^^^^^^^ function or associated item not found in `Mint`
    |
    = note: this error originates in the derive macro `Accounts` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `anchor_spl::token::Mint: Discriminator` is not satisfied
   --> programs/anchor-movie-review-program/src/lib.rs:127:30
    |
127 |     pub mint: Account<'info, Mint>,
    |                              ^^^^ the trait `Discriminator` is not implemented for `anchor_spl::token::Mint`
    |
    = help: the following other types implement trait `Discriminator`:
              InitializeTokenMint
              MovieAccountState
              __idl::IdlAccount
              anchor_lang::ProgramData
              anchor_lang::idl::IdlAccount
              instruction::AddMovieReview
              instruction::DeleteMovieReview
              instruction::UpdateMovieReview

error[E0599]: no function or associated item named `insert_types` found for struct `anchor_spl::token::Mint` in the current scope
   --> programs/anchor-movie-review-program/src/lib.rs:107:10
    |
107 | #[derive(Accounts)]
    |          ^^^^^^^^ function or associated item not found in `Mint`
    |
    = note: this error originates in the derive macro `Accounts` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0599]: no function or associated item named `create_type` found for struct `anchor_spl::token::TokenAccount` in the current scope
   --> programs/anchor-movie-review-program/src/lib.rs:107:10
    |
107 | #[derive(Accounts)]
    |          ^^^^^^^^ function or associated item not found in `TokenAccount`
    |
    = note: this error originates in the derive macro `Accounts` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `anchor_spl::token::TokenAccount: Discriminator` is not satisfied
   --> programs/anchor-movie-review-program/src/lib.rs:134:39
    |
134 |     pub token_account: Account<'info, TokenAccount>,
    |                                       ^^^^^^^^^^^^ the trait `Discriminator` is not implemented for `anchor_spl::token::TokenAccount`
    |
    = help: the following other types implement trait `Discriminator`:
              InitializeTokenMint
              MovieAccountState
              __idl::IdlAccount
              anchor_lang::ProgramData
              anchor_lang::idl::IdlAccount
              instruction::AddMovieReview
              instruction::DeleteMovieReview
              instruction::UpdateMovieReview

error[E0599]: no function or associated item named `insert_types` found for struct `anchor_spl::token::TokenAccount` in the current scope
   --> programs/anchor-movie-review-program/src/lib.rs:107:10
    |
107 | #[derive(Accounts)]
    |          ^^^^^^^^ function or associated item not found in `TokenAccount`
    |
    = note: this error originates in the derive macro `Accounts` (in Nightly builds, run with -Z macro-backtrace for more info)

Some errors have detailed explanations: E0277, E0599.
For more information about an error, try `rustc --explain E0277`.
error: could not compile `anchor-movie-review-program` (lib test) due to 9 previous errors
Error: Building IDL failed

Summary of Changes

Added a paragraph to the lesson that indicates what needs to be added to the Cargo.toml file in order for the code to compile successfully.