Enable codecov

[mirgee]

The codecov test panics were due to this change, mentioned on this and this issue. The error backtrace is:

test api::vcx::tests::test_import_after_init_fails ... thread '<unnamed>' panicked at 'attempted to leave type `linked_hash_map::Node<std::string::String, raw_statement::RawStatement>` uninitialized, which is invalid', /rustc/25c8c53dd994acb3f4f7c02fe6bb46076393f8b0/library/core/src/mem/mod.rs:658:9
stack backtrace:
   0: rust_begin_unwind
             at /rustc/25c8c53dd994acb3f4f7c02fe6bb46076393f8b0/library/std/src/panicking.rs:483
   1: core::panicking::panic_fmt
             at /rustc/25c8c53dd994acb3f4f7c02fe6bb46076393f8b0/library/core/src/panicking.rs:85
   2: core::panicking::panic
             at /rustc/25c8c53dd994acb3f4f7c02fe6bb46076393f8b0/library/core/src/panicking.rs:50
   3: linked_hash_map::LinkedHashMap<K,V,S>::insert
   4: <rusqlite::cache::CachedStatement as core::ops::drop::Drop>::drop
   5: <indy_wallet::storage::default::SQLiteStorage as indy_wallet::storage::WalletStorage>::add
   6: indy_wallet::wallet::Wallet::add
   7: indy_wallet::WalletService::add_record
   8: indy_wallet::WalletService::add_indy_object
   9: indy::commands::did::DidCommandExecutor::execute
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

To read: https://doc.rust-lang.org/nomicon/unchecked-uninit.html

[Patrik-Stas]

Perhaps could be fixed by updating rusqlite from which the error seems to be originating, libindy is now using 0.20.0, but 0.24.0 is available.
https://github.com/rusqlite/rusqlite/releases

Anyway, for codecov restoreation this fix this is ofcourse good enough. Good investigation 👍