ENH: Configure isolated builds and set up cibuildwheel

[effigies]

Builds on #13 and #14.

Incremental diff: effigies/gradunwarp@mnt/drop-fsl...enh/build

Closes #13.
Closes #14.

[effigies]

I believe the test failure was a one-off corrupt download from PyPI. Restarting the CI job should check that. This is ready for review.

[coalsont]

Looks reasonable as far as I can tell. Seems to still install with the old instructions on ubuntu 20.04/python3.8 at least (if the system numpy isn't installed, but that was already an issue in our version). Haven't tried anything more than the usage info.

[cyang31]

Looks good to me. The replacement of the command line with the nibabel module is really nice. I created a local env on macos, installed this module using this PR, run the test_gradient_unwarp.py and it works on my end.

[effigies]

I should note that I added some machinery for bumping the version across the three locations it's found in. It uses bumpver, which can be installed with pip or run through something like pipx:

❯ pipx run bumpver show         
INFO    - fetching tags from remote (to turn off use: -n / --no-fetch)
Current Version: 1.2.2.dev
PEP440         : 1.2.2.dev0

To update from a dev version, you can run bumpver update --tag final. Here I bump the minor version from 1.2 to 1.3 (using --dry to avoid making a commit or tag):

❯ pipx run bumpver update --minor --tag final --dry
INFO    - fetching tags from remote (to turn off use: -n / --no-fetch)
INFO    - Old Version: 1.2.2.dev
INFO    - New Version: 1.3.0
--- gradunwarp/core/globals.py
+++ gradunwarp/core/globals.py
@@ -6,7 +6,7 @@
 ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ##
 import logging
 
-VERSION = '1.2.2.dev'
+VERSION = '1.3.0'
 
 usage = '''
 gradient_unwarp infile outfile manufacturer -g <coefficient file> [optional arguments]
--- pyproject.toml
+++ pyproject.toml
@@ -13,7 +13,7 @@
 build-backend = "setuptools.build_meta"
 
 [tool.bumpver]
-current_version = "1.2.2.dev"
+current_version = "1.3.0"
 version_pattern = "MAJOR.MINOR.PATCH[.TAG]"
 commit_message = "bump version {old_version} -> {new_version}"
 tag_message = "{new_version}"
--- version.txt
+++ version.txt
@@ -1,2 +1,2 @@
-v1.2.2.dev
+v1.3.0
 

Dropping the --minor would update from 1.2.2.dev to 1.2.2.

Post-release, I would then do something like the following to update the dev version again:

❯ pipx run bumpver update --patch --tag dev --no-tag-commit

[effigies]

Forgot that I planned to make sure pip install . works with and without pre-running pip install -r requirements.txt. Now included as a test and works across all listed versions.

[coalsont]

I'm basically just waiting for this to stabilize before merging.

[effigies]

Ah, I think this is good to go. If more things come up, more pull requests can be made.