Move lightning-transaction-sync out of the main workspace

Because `lightning-transaction-sync` does not have an MSRV (and
because its dev-dependencies are huge), we can't build it by
default when devs run `cargo test`, so it is moved out of the
top-level workspace.

Author: TheBlueMatt

.github/workflows/build.yml

@@ -86,10 +86,10 @@ jobs:
         run: cargo update -p tokio --precise "1.14.0" --verbose
         env:
           CARGO_NET_GIT_FETCH_WITH_CLI: "true"
-      - name: Build on Rust ${{ matrix.toolchain }} with net-tokio and tx-sync
-        if: "matrix.build-net-tokio && !matrix.coverage && matrix.build-tx-sync"
+      - name: Build on Rust ${{ matrix.toolchain }} with net-tokio
+        if: "matrix.build-net-tokio && !matrix.coverage"
         run: cargo build --verbose --color always
-      - name: Build on Rust ${{ matrix.toolchain }} with net-tokio, tx-sync, and full code-linking for coverage generation
+      - name: Build on Rust ${{ matrix.toolchain }} with net-tokio, and full code-linking for coverage generation
         if: matrix.coverage
         run: RUSTFLAGS="-C link-dead-code" cargo build --verbose --color always
       - name: Build on Rust ${{ matrix.toolchain }}
@@ -138,9 +138,9 @@ jobs:
         run: |
           cd lightning && cargo test --verbose --color always --features backtrace
       - name: Test on Rust ${{ matrix.toolchain }} with net-tokio
-        if: "matrix.build-net-tokio && !matrix.coverage && matrix.build-tx-sync"
+        if: "matrix.build-net-tokio && !matrix.coverage"
         run: cargo test --verbose --color always
-      - name: Test on Rust ${{ matrix.toolchain }} with net-tokio, tx-sync, and full code-linking for coverage generation
+      - name: Test on Rust ${{ matrix.toolchain }} with net-tokio, and full code-linking for coverage generation
         if: matrix.coverage
         run: RUSTFLAGS="-C link-dead-code" cargo test --verbose --color always
       - name: Test no-std builds on Rust ${{ matrix.toolchain }}

Cargo.toml

@@ -3,7 +3,6 @@
 members = [
     "lightning",
     "lightning-block-sync",
-    "lightning-transaction-sync",
     "lightning-invoice",
     "lightning-net-tokio",
     "lightning-persister",
@@ -13,6 +12,7 @@ members = [
 
 exclude = [
     "lightning-custom-message",
+    "lightning-transaction-sync",
     "no-std-check",
 ]