Node 10 Support (#27)

* chore: drop support for node 6

* fix: installation on node 10

This PR swaps the original memwatch-next with another fork to support node 10+.

* fix(test): make more iterations to detect leakage

The original setting for memory pressure is too subtle to be detected. This
commit changes the number of test iteration to a much higher number so that
leakage can be more easily detected.

.travis.yml

@@ -7,7 +7,8 @@ addons:
       - g++-4.8
 node_js:
   - node    # Latest
+  - 9.0
+  - 8.11    # LTS
   - 7.0
-  - 6.0
 before_install:
   - if [[ $TRAVIS_OS_NAME == "linux" ]]; then export CXX=g++-4.8; fi

README.md

@@ -131,7 +131,7 @@ Test for memory leaks. Will return a rejecting promise when a leak is recognized
 ### Result object
 
 Properties:
-* `heapDiffs` - An array of heap diffs as created by `memwatch-next`
+* `heapDiffs` - An array of heap diffs as created by `node-memwatch`
 * `iterations` - The number of iterator runs per heap diff
 * `gcollections` - The number of garbage collections / heap diffs performed
 
@@ -160,7 +160,7 @@ Will make the library write a detailed heap diff JSON to the file system. Make s
 
 ## Under the Hood
 
-Leakage uses `memwatch-next` to trigger the garbage collector and create heap diffs.
+Leakage uses `node-memwatch` to trigger the garbage collector and create heap diffs.
 
 You just specify an iterator function. It will be run 30 times by default then a garbage collection will be performed and a heap snapshot will be made. This process is iterated 6 times by default to collect several heap diffs, since especially in async tests there is always a bit of background noise.
 
@@ -169,7 +169,7 @@ If the heap size increased over more than `[heapDiffCount * 2 / 3]` subsequent g
 
 ## Travis CI
 
-You might want your leakage tests to be run by your CI service. There is an issue with Travis CI's linux containers, `g++` and a transitive dependency of `memwatch-next` ([nan](https://www.npmjs.com/package/nan)).
+You might want your leakage tests to be run by your CI service. There is an issue with Travis CI's linux containers, `g++` and a transitive dependency of `node-memwatch` ([nan](https://www.npmjs.com/package/nan)).
 
 Fortunately there is a fix: You need to install and use version `4.8` of `g++` in order to compile the dependency.
 

lib/index.js

@@ -21,7 +21,7 @@
  */
 
 const fs = require('fs')
-const memwatch = require('memwatch-next')
+const memwatch = require('@airbnb/node-memwatch')
 const minimist = require('minimist')
 const path = require('path')
 const { createResult } = require('./result')