#26 broke the build- fix histogram tests and keep compatibility with older golang versions

[bejelith]

• Build broke by #26 so had to change go.mod.
• Reworked tests to make more resilient in case of dependency changes.

[bejelith]

is there anybody working on this repository ? @joannak-vmware @vikramraman @laullon

[joannatk]

Hi @bejelith , I added myself as reviewer since I did the version bump, and will add an additional reviewer soon

[bejelith]

I cannot merge it as im not authorized

[joannatk]

@bejelith , have merged changes.