Do not log by default

[sanmai]

In the light of #1430 it doesn't make sense to keep Infection suggesting logging at all times. Keeping old behavior will mean that Infection will use 66% more memory where it could not.

This PR:

• Updates configuration master to do not log by default.
• Covered by tests

[maks-rafalko]

merged to master edfe1bd

[theofidry]

I wonder if it's wise though: when you kill everything that's all good but as soon as you got one, then what? You need to run infection again with a log file this time

[sanmai]

Then just -s, no?

[theofidry]

WDYM?

[sanmai]

I always use Infection with --show-mutations, no logging needed.

[theofidry]

Ah I see. Still it's not the default this may just lead to very confused users. What do you think of enabling --show-mutations automatically there is no log file?

[sanmai]

This also be confusing, e.g. when a user expects --show-mutations to be enabled automatically, adds a log file, and sees it no longer enabled without clear reason. This can be alleviated by a adding a note in the output, but then we could consider other similar ways. For example:

• We could add "Tip: to show escaped mutations run Infection with --show-mutations" somewhere after the results.
• We could have --show-mutations enabled at all times unconditionally, but showing it above metrics.

[maks-rafalko]

I would vote for

We could add "Tip: to show escaped mutations run Infection with --show-mutations" somewhere after the results.