CI: unary operator expected error in log files
fix error in azure log

```
ci/setup_env.sh: line 121: [: ==: unary operator expected
```

Was this causing any other issues or was our CI just not running DB tests on travis? causing a spurious message in the azure logs. it's probably no big deal. Travis didn't run, so will need to re-run to check this didn't break anything on the Travis front. so it appears Travis is not run for draft PRs. marking this as ready for review, but's it not ready! need to check the Travis logs. # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=h1) Report
> Merging [#26547](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/998a0deea39f11fa06071af77cc1afba65900330?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/26547/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #26547      +/-   ##
==========================================
- Coverage   91.77%   91.76%   -0.01%     
==========================================
  Files         174      174              
  Lines       50638    50638              
==========================================
- Hits        46471    46468       -3     
- Misses       4167     4170       +3
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.3% <ø> (ø)` | :arrow_up: |
| #single | `41.69% <ø> (-0.07%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/26547/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `78.94% <0%> (-10.53%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/26547/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97% <0%> (-0.12%)` | :arrow_down: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/26547/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `90.7% <0%> (+0.1%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=footer). Last update [998a0de...ce2b4d0](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=h1) Report
> Merging [#26547](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/7629a182f34d0374cb329e07076fba16605853ee?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/26547/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #26547      +/-   ##
==========================================
- Coverage   91.77%   91.76%   -0.01%     
==========================================
  Files         174      174              
  Lines       50642    50642              
==========================================
- Hits        46476    46471       -5     
- Misses       4166     4171       +5
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.3% <ø> (ø)` | :arrow_up: |
| #single | `41.67% <ø> (-0.11%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/26547/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `78.94% <0%> (-10.53%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/26547/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97% <0%> (-0.12%)` | :arrow_down: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/26547/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `90.6% <0%> (-0.11%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=footer). Last update [7629a18...a7a0adf](https://codecov.io/gh/pandas-dev/pandas/pull/26547?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 > or was our CI just not running DB tests on travis?

it's the other way round. db tests running on Travis only. lgtm. pls verify that the message is coming on the right builds; merge when ready. > pls verify that the message is coming on the right builds

checked.