CircleCI updates: Unify requirements, drop conda, refactor to reduce duplication (#3164)

* Install requirements for orca test from same requirements.txt file
* Use same circleci image for orca job as optional jobs
* remove editable plotly-geo from optional requirements.txt
* reduce duplication with circleci commands
* use underscores for command names
* Update circle to 2.1
* Use optional requirements.txt from percy CI job

Author: jonmmease