Do not install requirements from github.txt in editable mode
Merge pull request #6038 from edx/zoldak/not-editable-mode

Do not install requirements from github.txt in editable mode
s/pylint: disable=W0621/pylint: disable=redefined-outer-name/
s/pylint: disable=C0111/pylint: disable=missing-docstring/
s/pylint: disable=E0611/pylint: disable=no-name-in-module/
s/pylint: disable=C0103/pylint: disable=invalid-name/
Remove outdated pylint disable
s/pylint: disable=E1101/pylint: disable=no-member/
s/pylint: disable=E1120/pylint: disable=no-value-for-parameter/
s/pylint: disable=E1103/pylint: disable=maybe-no-member/
s/pylint: disable=E1111,E1124/pylint: disable=assignment-from-no-return,redundant-keyword-arg/
s/pylint: disable=E0604/pylint: disable=invalid-all-object/
s/pylint: disable=E1121/pylint: disable=too-many-function-args/
s/pylint: disable=E0702/pylint: disable=raising-bad-type/
s/pylint: disable=E1102/pylint: disable=not-callable/
s/disable=E0213,W0613/disable=no-self-argument,unused-argument/
Fix exposed pylint violations
s/pylint: disable=F0401/pylint: disable=import-error/
s/pylint: disable=R0915/pylint: disable=too-many-statements/
s/pylint: disable=R0924/pylint: disable=incomplete-protocol/