NR Log Parser

Currently there is only 1 function, search, which will search for lines matching criteria, and then write those lines to a specified output file.

Usage

It is possible to match log lines using at least one of:

log level: This will match lines with a specific log level, e.g.
```
nrlp search -f newrelic-infra.log --level error
```
component: This will match lines with a specific component, e.g.
```
nrlp search -f newrelic-infra.log --component Config
```
custom: Custom queries are look at substrings within the line. They can be comma separated to search for multiple substrings, e.g.
```
nrlp search -f newrelic-infra.log --custom 'msg="Using Network Interface Filter Set",filter=index-1,interface=tun' 
```
time filter: Time filter queries can be used to only evaluate log lines generated before, after, or before + after (in between) a specified UTC time, e.g.
```
nrlp search -f newrelic-infra.log --before "2019-10-18 15:05:00" --after "2019-10-18 15:00:00"
```

You can use multiple filters in order to find very specific logs.