Podfile.lock version ignored on initial install

[icecrystal23]

I was testing out this plugin and noticed that it upgraded a library when I first tried it out. It ignored the version in our Podfile.lock and instead installed the highest compatible version matching the version in the Podfile (we have '~> 5.2.0' in the Podfile, 5.2.5 in Podfile.lock and this plugin used 5.2.7

[biocross]

For now, I'd recommend specifying the exact version in your MergeFile, since the plugin does not have context from the Podfile.lock and it only relies on the Mergefile. However, this is an interesting suggestion: I will look into this and see if the plugin can start reading the Podfile.lock as well. Thank you!

[biocross]

@icecrystal23 I was able to fix this issue by copying the top level Podfile.lock into each group's temporary pod install. That helps constraint the version of the each pod in the group during the internal pod install.

I'll release the fix soon with a new flag to allow disabling this feature.