* Support pow() as an argument for derivative()
Add support for the pow() function as an argument for math.derivative().
Fixes#1259.
* Unit tests for derivatives of pow()
* Support for derivate of pow() function
* chore(package): update standard to version 12.0.0
* update to new lint version with --fix
I believe this mainly adds whitespace to `{}`'s.
* Replace assert.equal with assert.strictEqual
This breaks a lot of tests which I will endevour to fix in the next
commits.
* Fix most errors due to assert.strictEquals
Some instances of `strictEquals` are replaced by `deepEquals`.
`toString` has been used to make some string comparisions explicit.
Tests will still fail untill #1236 and #1237 are fixed.
* Fix assertion erros due to -0
With node 10, assert.strictEqual no longer considers `0 === -0`.
I missed these first time round as I was using node 8.
* Put toString correct side of bracket
I was converting the constructor to a string rather
than the result of the computation. Oops.
* Fixed#1236: quantileSeq has inconsistant return
* Update package-lock
* Fixed#1237: norm sometimes returning a complex number instead of number
* Fix cli tests
* More changes for standardjs, and fixes in unit tests
Fix of bug fixes in `rationalize.js`, also changing `simplify.js` and `simplifyConstant.js` and more 2 bugs in `simplify.js` and `simplifyconstant.js` in order to be possible passing in `Travis` test.
**Bugs in `simplifyConstant.js` and `simplify.js`**
1. `simplifyConstant.js` - I've changed `new ConstantNode(stringNumber, 'number')` to `new ConstantNode(number)`
1. `simplify.js` - Due to problems with a number node with string type, I've added `!isNaN(node.value)))` in number type test condition
**Bugs in `rationalize.js`**
3. I've fixed negative power exponents and decimals coefficients troubles. The decimals coefficients problem has led to the need to add a new feature in `simplify.js ` and `simplifyConstant.js` (next topic)
**New feature in `simplify.js` and `simplifyConstant.js`**
4. New rule type (string), whose valid values are in `listCommStrings` new variable. The only string rule accepted so far is to turn off exact fraction conversion in `simplifyConstant.js`
