allow SELF in st_tmpl (#240)

* allow SELF in st_tmpl

* add some tests

* Update src/backends/plonky2/circuits/mainpod.rs

Co-authored-by: Ahmad Afuni <root@ahmadafuni.com>

---------

Co-authored-by: Ahmad Afuni <root@ahmadafuni.com>

.github/workflows/build.yml

@@ -0,0 +1,25 @@
+name: Rust Build with features
+
+on:
+  pull_request:
+    branches: [ main ]
+    types: [ready_for_review, opened, synchronize, reopened]
+  push:
+    branches: [ main ]
+
+jobs:
+  test:
+    if: github.event.pull_request.draft == false
+    name: Rust tests
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Rust
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: stable
+    - name: Build default
+      run: cargo build
+    - name: Build metrics
+      run: cargo build --features metrics
+