wip(lib_core): introduce database module

refs: #5

Cargo.lock

@@ -110,6 +110,28 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "async-stream"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b5a71a6f37880a80d1d7f19efd781e4b5de42c88f0722cc13bcb6cc2cfe8476"
+dependencies = [
+ "async-stream-impl",
+ "futures-core",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "async-stream-impl"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7c24de15d275a1ecfd47a380fb4d5ec9bfe0933f309ed5e705b775596a3574d"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "atoi"
 version = "2.0.0"
@@ -941,6 +963,7 @@ dependencies = [
 name = "lib_sync_core"
 version = "0.1.0"
 dependencies = [
+ "async-stream",
  "chrono",
  "clap",
  "directories",