improve specification versioning

Signed-off-by: Onur Özkan <work@onurozkan.dev>

kaptan-spec/tests/ui/fail_missing_sidecar.rs

@@ -1,6 +1,6 @@
 use kaptan_spec::spec;
 
-#[spec("fail_missing_sidecar.v0.1.0.spec.md")]
+#[spec("fail_missing_sidecar.spec.md")]
 struct MissingSpec;
 
 fn main() {

kaptan-spec/tests/ui/fail_missing_sidecar.stderr

@@ -1,5 +1,5 @@
-error: couldn't read `$DIR/tests/ui/fail_missing_sidecar.v0.1.0.spec.md`: No such file or directory (os error 2)
+error: couldn't read `$DIR/tests/ui/fail_missing_sidecar.spec.md`: No such file or directory (os error 2)
  --> tests/ui/fail_missing_sidecar.rs:3:1
   |
-3 | #[spec("fail_missing_sidecar.v0.1.0.spec.md")]
-  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+3 | #[spec("fail_missing_sidecar.spec.md")]
+  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

kaptan-spec/tests/ui/flight_core_contract.rs

@@ -1,6 +1,6 @@
 use kaptan_spec::spec;
 
-#[spec("flight_core_contract.v0.1.0.spec.md")]
+#[spec("flight_core_contract.spec.md")]
 struct FlightCore;
 
 fn main() {

kaptan-spec/tests/ui/flight_core_contract.spec.md

@@ -0,0 +1,25 @@
+# --- version: 0.1.0 ---
+
+---
+title: Flight core contract
+status: in-progress
+owners:
+  - Flight Systems <flight@example.com>
+---
+
+## Contract
+
+Initial control contract.
+
+# --- version: 0.2.0 ---
+
+---
+title: Flight core contract
+status: implemented
+owners:
+  - Flight Systems <flight@example.com>
+---
+
+## Contract
+
+Revised control contract.

kaptan-spec/tests/ui/flight_core_contract.v0.1.0.spec.md

@@ -1,10 +0,0 @@
----
-title: Flight core contract
-status: in-progress
-owners:
-  - Test Name <name@test.com>
----
-
-# Summary
-
-Minimal spec for compile-time linkage testing.