Load images fix

[nilseling]

Addresses #55

[codecov[bot]]

Codecov Report

All modified lines are covered by tests :white_check_mark:

Comparison is base (b04e1a6) 87.30% compared to head (a507bcb) 87.31%. Report is 3 commits behind head on devel.

:exclamation: Current head a507bcb differs from pull request most recent head 645a3e0. Consider uploading reports for the commit 645a3e0 to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## devel #83 +/- ## ======================================= Coverage 87.30% 87.31% ======================================= Files 18 18 Lines 2750 2751 +1 ======================================= + Hits 2401 2402 +1 Misses 349 349 ``` | [Files](https://app.codecov.io/gh/BodenmillerGroup/cytomapper/pull/83?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=BodenmillerGroup) | Coverage Δ | | |---|---|---| | [R/validityChecks.R](https://app.codecov.io/gh/BodenmillerGroup/cytomapper/pull/83?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=BodenmillerGroup#diff-Ui92YWxpZGl0eUNoZWNrcy5S) | `97.15% <100.00%> (+<0.01%)` | :arrow_up: |

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.