Remove the concept of named, identifiable runs.

StarBoss is meant for building things checked into the repo It is also designed
around repeatable builds. So it makes the assumption that running a build step
for a specific version of a project will always result in the same output. So
runs are identified by the project, build step, and version.

src/main/nim/strawboss.nim

@@ -1,4 +1,4 @@
-import cliutils, docopt, os, sequtils, tempfile, uuids
+import cliutils, docopt, os, sequtils, tempfile
 
 import strawbosspkg/configuration
 import strawbosspkg/core
@@ -30,9 +30,6 @@ Options
 
   -r --reference <ref>        Build the project at this commit reference.
 
-  -i --run-id <id>            Use the given UUID as the run ID. If not given, a
-                              new UUID is generated for this run.
-
   -w --workspace <workspace>  Use the given directory as the build workspace.
 
 """
@@ -57,7 +54,6 @@ Options
 
     try:
       let req = RunRequest(
-        id: if args["--run-id"]: parseUUID($args["--run-id"]) else: genUUID(),
         projectName: $args["<project>"],
         stepName: $args["<step>"],
         buildRef: if args["--reference"]: $args["--reference"] else: nil,