CI: don't show miniconda output on install / numpy 1.14 compat
closes #18123
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/18157?src=pr&el=h1) Report
> Merging [#18157](https://codecov.io/gh/pandas-dev/pandas/pull/18157?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/c8aad92c44098caf7d5875bd0803a2abffb3b34a?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `66.66%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/18157/graphs/tree.svg?token=eZ4WkYLtcO&height=150&width=650&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/18157?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #18157      +/-   ##
==========================================
- Coverage    91.4%   91.38%   -0.02%     
==========================================
  Files         163      163              
  Lines       50068    50068              
==========================================
- Hits        45764    45755       -9     
- Misses       4304     4313       +9
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.19% <66.66%> (ø)` | :arrow_up: |
| #single | `40.33% <66.66%> (-0.06%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/18157?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/compat/\_\_init\_\_.py](https://codecov.io/gh/pandas-dev/pandas/pull/18157?src=pr&el=tree#diff-cGFuZGFzL2NvbXBhdC9fX2luaXRfXy5weQ==) | `58.1% <66.66%> (ø)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/18157?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/18157?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.8% <0%> (-0.1%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/18157?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/18157?src=pr&el=footer). Last update [c8aad92...0055c61](https://codecov.io/gh/pandas-dev/pandas/pull/18157?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
