Temporarily remove no_std support

[digorithm]

Currently, we created a no_std feature to handle wasm builds. However, this causes cargo build --all-features to break, which shouldn't happen. Instead, we should have a std feature-set set as default, as per the official Rust docs:

For example, if you want to optionally support no_std environments, do not use a no_std feature. Instead, use a std feature that enables std. For example: (https://doc.rust-lang.org/cargo/reference/features.html#feature-unification)

This PR temporarily removes the no_std so the CI won't break and this issue (#62) captures the future work that needs to be done in order to properly enable no_std compatibility.

Closes #52.

[adlerjohn]

CI failing for some reason

[Voxelot]

You'll also need to update CI to run a build/test in no-std mode. Something similar to this: https://github.com/FuelLabs/fuel-types/blob/master/.github/workflows/ci.yml#L49

    - name: Build no-std
      uses: actions-rs/cargo@v1
      with:
        command: build
        args: --verbose --target thumbv6m-none-eabi --no-default-features

[digorithm]

Uuuugh, this is very weird. The following test https://github.com/FuelLabs/fuels-rs/blob/master/fuels-rs/tests/calls.rs#L17 is failing because forc can't build this very simple Sway script (https://github.com/FuelLabs/fuels-rs/blob/master/fuels-abigen-macro/tests/test_projects/simple_script/src/main.sw).

However, this is only happening in this CI server (!), and locally I can build it just fine:

simple_script git:(rodrigo/no-std-config) forc build
  Compiled library "core".
  Compiled library "core".
  Compiled library "lib-std" with 2 warnings.
  Compiled script "Fuel example project".
  Bytecode size is 396 bytes.

Crazy, uh? I then decided to put an #[ignore] on this failing test, because it honestly isn't testing anything special that the main harness file isn't testing... and the CI passes.

Note that this is happening everywhere else, not just this branch. Even on master that was passing a couple of days ago. That leads me to believe it isn't on fuels-rs, a small likelihood that's on forc, and a pretty big chance that Github Actions is doing something fishy.

cc @adlerjohn @Voxelot @vnepveu

Edit: for now I'll keep this failing test as #[ignore]. I'm still working through the no_std refactoring, so the builds after this comment will be failing for different reasons.

[digorithm]

Update

After a discussion that happened in the infra sync call with @Voxelot and @tjsharp1, we've decided to unblock the fuels-rs build by simplifying things (no no_std compatibility for now), and then, in another issue, I'll do some refactoring to turn the necessary bits of fuels-rs no_std so that it won't impact the indexer. In the meantime, the indexer should continue using the current fuels-rs pinned version.

[adlerjohn]

Can you also update the description of the PR? I'm not actually sure what this PR does.

[digorithm]

Can you also update the description of the PR? I'm not actually sure what this PR does.

Nice catch, that wasn't making any sense anymore. Title and description updated.

[adlerjohn]

LGTM, but would prefer weigh-in from @Voxelot