Codecov: ignored Display and Debug for coverage

- also some changes for tarpaulin and codecov to only execute relevant codes

.codecov.yml

@@ -1,10 +1,8 @@
-codecov:
-  ci:
-    - cirrus-ci.com
 coverage:
   range: 70...100
 ignore:
   - "nes_test"
   - "tests.rs"
   - "**/tests.rs"
   - "tests"
+  - "**/tests"

.github/workflows/rust.yml

@@ -31,5 +31,5 @@ jobs:
   # - name: Run tests
   #   run: cargo test --verbose
     - name: Run test cargo-tarpaulin
-      run: cargo tarpaulin --workspace -v --lib -o Xml
+      run: cargo tarpaulin --workspace -e nes_test -v -o Html
     - uses: codecov/codecov-action@v1.0.11

cpu6502/src/instruction.rs

@@ -316,6 +316,7 @@ impl Instruction {
     }
 }
 
+#[cfg(not(tarpaulin_include))]
 impl Display for Opcode {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         use Opcode::*;
@@ -391,6 +392,7 @@ impl Display for Opcode {
     }
 }
 
+#[cfg(not(tarpaulin_include))]
 impl Display for Instruction {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         use AddressingMode::*;