Keep icu_datetime compatible and bump crate versions to 0.1.1

[ghost]

icu_datetime changed the location of MockDateTime structure, so I put it back on the icu_datetime::date module. Also, if possible, would like if you could publish it (and icu_testdata) to crates.io.

[coveralls]

Pull Request Test Coverage Report for Build b5dd59e801f5741e1311b4b6316345ffd214103a-PR-531

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage remained the same at 72.707%

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Files with Coverage Reduction	New Missed Lines	%
components/datetime/src/date.rs	1	28.75%

Totals
Change from base Build 9b0fa09152aea4de2f8a37628d0bebb9ebb50f3d:	0.0%
Covered Lines:	4851
Relevant Lines:	6672

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💛 - Coveralls

[sffc]

I'm not opposed to releasing 0.1.1 of icu_testdata to fix the bug from #527, but I don't want to release 0.2 of icu_datetime until we're ready with all the pending feature work. There are several open PRs to commit further changes to icu_datetime.

Note: 0.1 is a very early alpha release of ICU4X, and we aren't yet giving any guarantees about it being stable or production-ready.

[ghost]

I bumped icu_datetime version to 0.1.1 this time. In a previous PR I bumped it to 0.2 because it was not backwards-compatible with MockDateTime.