Fix bug around spawning worker processes.

We were expecting to find the path to the `strawboss` binary implicitly from
the environment, which meant that configuration was also implicit, and required
more setup. Now the path to the binary is explicit in the StrawBoss runtime
configuration, and the path to the configuration file can also be explicitly given.

src/main/nim/strawbosspkg/configuration.nim

@@ -37,7 +37,9 @@ type
   StrawBossConfig* = object
     artifactsRepo*: string
     authSecret*: string
+    filePath*: string
     debug*: bool
+    pathToExe*: string
     projects*: seq[ProjectDef]
     pwdCost*: int8
     users*: seq[UserRef]
@@ -131,6 +133,7 @@ proc loadStrawBossConfig*(cfgFile: string): StrawBossConfig =
     raiseEx "strawboss config file not found: " & cfgFile
 
   result = parseStrawBossConfig(parseFile(cfgFile))
+  result.filePath = cfgFile
 
 proc loadProjectConfig*(cfgFile: string): ProjectConfig =
   if not existsFile(cfgFile):