fix: add space after annotation in typeBounds

[clementdessoude]

What changed with this PR:

Example

// Input
public class Foo<T> {

  public <U extends @NotNull T> void example(U u) {}

  public <U extends com.java.Any.@NotNull T> void example(U u) {}
}

// Prettier 1.6.1
public class Foo<T> {

  public <U extends @NotNullT> void example(U u) {}

  public <U extends com.java.Any.@NotNullT> void example(U u) {}
}

// Next
public class Foo<T> {

  public <U extends @NotNull T> void example(U u) {}

  public <U extends com.java.Any.@NotNull T> void example(U u) {}
}

Relative issues or prs:

Fix #536