Default to "^" instead of "~" for semantic version of dependencies

[mikolalysenko]

"~" is confusing and undermines the purpose of semantic versioning. Consider either:

• Default locking version strings to a specific version (ie no automatic upgrading)
• Or default to properly following semantic versioning.

The current behavior using "~" is highly inconsistent. It does not protect users from malicious or accidental mistakes in package upgrades, since it still automatically upgrades patch versions. And it does not properly follow semver, so it does not ensure the current package is at the latest version.

Of the two options, I lean toward the second as it encourages users to choose to follow semantic versioning.

[robertkowalski]

Merged as c77a6f7 - thanks!