Renaming workdir into workingDir

[l0rd]

Example with proposed changes:

commands:
 - exec:
     commandLine: "./buildSchema.sh"
     workingDir: "~/schemaScripts"
     component: build-tools
     alias: buildSchema

[l0rd]

cc @johnmcollier @elsony

[davidfestal]

There is already a workDir attribute for the exec commands in the current proposal on master.
But it was not mentioned in any samples.
Using it would be like that:

  - exec:
      commandLine: "./buildSchema.sh"
      component: build-tools
      alias: buildSchema
      workdir: /projects/myProject

Of course the name can be changed if necessary.

[l0rd]

Description and title changed with a new proposal (renaming workdir) after review.

[davidfestal]

Implemented