Flow storage copying fails with spaces in flow.name

[joshmeek]

Step 1/9 : FROM python:3.6
 ---> 2bb3204ab1d1
Step 2/9 : RUN pip install pip --upgrade
 ---> Using cache
 ---> 4d8b101e2933
Step 3/9 : RUN pip install wheel
 ---> Using cache
 ---> 7389d69ba240
Step 4/9 : RUN mkdir /root/.prefect/
 ---> Using cache
 ---> 10619fcde458
Step 5/9 : COPY Test Flow.flow /root/.prefect/TestFlow.prefect
Traceback (most recent call last):
  File "managed_agent_testing.py", line 15, in <module>
    f.deploy(project_name="Test Project")
  File "/Users/josh/Desktop/code/prefect/src/prefect/core/flow.py", line 1361, in deploy
    set_schedule_inactive=set_schedule_inactive,
  File "/Users/josh/Desktop/code/prefect/src/prefect/client/client.py", line 357, in deploy
    serializedFlow=flow.serialize(build=build),
  File "/Users/josh/Desktop/code/prefect/src/prefect/core/flow.py", line 1116, in serialize
    storage = self.storage.build()  # type: Optional[Storage]
  File "/Users/josh/Desktop/code/prefect/src/prefect/environments/storage/docker.py", line 170, in build
    image_name, image_tag = self.build_image(push=push)
  File "/Users/josh/Desktop/code/prefect/src/prefect/environments/storage/docker.py", line 219, in build_image
    "Your flow failed to deserialize in the container; please ensure that all necessary files and dependencies have been included."
prefect.utilities.exceptions.SerializationError: Your flow failed to deserialize in the container; please ensure that all necessary files and dependencies have been included.

Code to reproduce:

from prefect import task, Flow
from prefect.environments.storage import Docker


@task
def my_task():
    print("ASDF")


with Flow(
    "Test Flow", storage=Docker(...)
) as f:
    t1 = my_task()

f.deploy(project_name="Test Project")

COPY Test Flow.flow /root/.prefect/TestFlow.prefect the whitespace between Test and Flow.flow is the issue. We need to sanitize this by replacing it with a special character

[cicdw]

Since we already require slugify, we could use that as a quick off-the-shelf solution:

import slugify                  
                                                                                                                            
slugify.slugify("Test Flow")                                                                                                                                
## 'test-flow'

[jlowin]

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