Documented hooks not supported

[Torgen]

In Mocha, the before/after/beforeEach/afterEach hooks take a description and a function; if you pass only a function, it generates a description for you. This package's versions of those hooks take only a function. Someone reading the mocha docs (like me) and attempting to annotate their hooks would then get an opaque error like:

${testsuite_name} "before each" hook: wrappedFunction for "${testcase_name}":
TypeError: fn.call is not a function
at run (packages/practicalmeteor_mocha-core.js:90:16)