* chore(package): update @babel/core to version 7.4.3
* chore(package): update @babel/preset-env to version 7.4.3
* chore(package): update lockfile package-lock.json
* initial implementation of multidimensional std and var
* consolidated std function into var, cleaned up the interface for var, fixed bias correction
* added documentation of variable axis for std and var
* updated documentation for std and var
* changed the order of normalization and dimension for a three parameter input in the functions
* updated documentation for var and std
* add transform expressions for std and var with variable axis
* added test coverage for std and var with a variable axis
* update to documentation
* change n dim std to use apply function
* fixed tests, removed unnecessary code, updated docs
* fixed typo in docs
* update docs to remove a type
* changed location of apply function
* updated tests to use deepStrictEqual to pass linter
* adding test coverage for var.transform and std.transform
* chore(package): update @babel/core to version 7.4.0
* chore(package): update @babel/preset-env to version 7.4.0
* chore(package): update @babel/register to version 7.4.0
* chore(package): update lockfile package-lock.json
* add placeholder for apply function
* added apply function
* add test coverage for apply utility
* stylsitic name change in apply source code
* stylistic format change to test
* improved description of function parameters
* moved the apply function to the public matrix functions
* update location and reference of unit test
* fixed function reference paths in apply for location in function
* changed path to apply in apply.test
* make apply a typed function, update unit test
* added typing error test to coverage
* remove apply.test.js from the utils test function
* added transform function for apply
* add unit test for apply.transform.js
* Fixed unit base recognition and formatting for user-defined units
* Began writing tests for range
* Use fuzzy comparisons for detecting range endpoint
* Fixed unit base recognition and formatting for user-defined units
* Manually copied work from another branch
* Removed semicolons
* Replaced assert.equal with assert.strictEqual
* Added support for bignumber
* Replaced var with const
* 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
