entity-manager: constructor arg to load config

Introduce a constructor arg to point EM to directories to load
configuration from.

This enables running unit tests without depending on a specific
directory layout from our rofs.

Tested: on Tyan S8030. Config parsed as expected.

```
Oct 02 11:22:52 s8030-bmc-30303035c0c1 systemd[1]: Starting Entity Manager...
Oct 02 11:22:52 s8030-bmc-30303035c0c1 systemd[1]: Started Entity Manager.
Oct 02 11:23:02 s8030-bmc-30303035c0c1 entity-manager[8265]: There's still template variable $PRODUCT_PART_NUMBER un-replaced. Removing it from the string.
Oct 02 11:23:02 s8030-bmc-30303035c0c1 entity-manager[8265]: There's still template variable $PRODUCT_ASSET_TAG un-replaced. Removing it from the string.
Oct 02 11:23:02 s8030-bmc-30303035c0c1 entity-manager[8265]: There's still template variable $PRODUCT_ASSET_TAG un-replaced. Removing it from the string.
Oct 02 11:23:02 s8030-bmc-30303035c0c1 entity-manager[8265]: There's still template variable $PRODUCT_ASSET_TAG un-replaced. Removing it from the string.
Oct 02 11:23:02 s8030-bmc-30303035c0c1 entity-manager[8265]: There's still template variable $PRODUCT_PART_NUMBER un-replaced. Removing it from the string.
Oct 02 11:23:04 s8030-bmc-30303035c0c1 entity-manager[8265]: Inventory Added: Supermicro PWS 920P SQ 0
Oct 02 11:23:04 s8030-bmc-30303035c0c1 entity-manager[8265]: Inventory Added: Supermicro PWS 920P SQ 1
Oct 02 11:23:04 s8030-bmc-30303035c0c1 entity-manager[8265]: Inventory Added: Tyan S8030 Baseboard
Oct 02 11:23:04 s8030-bmc-30303035c0c1 entity-manager[8265]: Inventory Added: MBX 1.57 Chassis
```

Change-Id: I8ce297847d3cafe2e2ae2040e9db261dc1d8f426
Signed-off-by: Alexander Hansen <alexander.hansen@9elements.com>
diff --git a/src/utils.cpp b/src/utils.cpp
index d88df36..b5bac09 100644
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -40,7 +40,7 @@
     return true;
 }
 
-bool findFiles(const std::vector<fs::path>&& dirPaths,
+bool findFiles(const std::vector<fs::path>& dirPaths,
                const std::string& matchString,
                std::vector<fs::path>& foundPaths)
 {