Fix anyhow dependency issues (#208)

- Do not require backtrace feature
- Starting version 1.0.77, anyhow gathers backtrace is std feature (enabled by default)
  is specified even if backtrace feature is not enabled.
  Therefore specify default features as false.
- Specify version 1.0.45 since that is the minimul version required to successfully
  compile regorus

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

Cargo.toml

@@ -69,7 +69,7 @@ full-opa = [
 opa-testutil = []
 
 [dependencies]
-anyhow = {version = "1.0.66", features = ["backtrace"] }
+anyhow = { version = "1.0.45", default-features=false }
 serde = {version = "1.0.150", features = ["derive", "rc"] }
 serde_json = "1.0.89"
 serde_yaml = {version = "0.9.16", optional = true }
@@ -108,7 +108,7 @@ test-generator = "0.3.1"
 walkdir = "2.3.2"
 
 [build-dependencies]
-anyhow = "1.0.66"
+anyhow = "1.0"
 
 [profile.release]
 debug = true