Users desire to use environment variable expansions in few places, namely `working_directory` and in the environment section.
Currently, we treat all values as literals and no interpolation is supported.
Frequent patters for desiring the feature is:
For working_directory, the workaround is nuisance but is somewhat reasonable.
For the environment case, the workaround currently is for users to use an export in the command rather than the environment variable section - which is just annoying...
- run: command: | export PATH=/go/bin:$PATH go-vet .... # instead of - run: command: go-vet ... environment: PATH=/go/bin:$PATH
1.0 uses the `export` syntax for setting environment variables. This may be sufficient in 2.0 - but it is a bit verbose.